CHAPTER 4 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT for SALE OR DISTRIBUTION NOT for SALE OR DISTRIBUTION

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CHAPTER 4 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 106 3/12/14 9:24 PM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Identifying Locking © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning,4 LLC DevicesNOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Primary Learning Objectives © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEAfter reading OR DISTRIBUTIONthis chapter, you will be able to: NOT FOR SALE OR DISTRIBUTION 1. Identify types of threads, nuts and bolts. (pp. 109–111, 113) 2. Identify types of washers and screws. (pp. 108–109, 111–112) 3. Use a torque wrench to tension nuts. (pp. 115–119) 4. Identify pins and© keys. Jones (pp. 119–121) & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Knowledge Objectives

After© readingJones this & chapter,Bartlett you Learning, will be able to: LLC © Jones & Bartlett Learning, LLC 1.NOT Identify FOR locking SALE devices OR and DISTRIBUTION tools. (pp. 108–114) NOT FOR SALE OR DISTRIBUTION 2. Describe fasteners and torque. (pp. 114–115) 3. Identify locking device measuring tools. (pp. 115–119) 4. Describe helical inserts. (p. 119) © Jones & Bartlett5. Identify Learning, locking pins and LLC keys. (pp. 119–121) © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Skills Objectives © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC After reading this chapter, you will be able to: NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 1. Use a torque wrench and torque angle gauge. (p. 119) PROCEDURE 4-1 2. Remove and install split pins. (p. 119) PROCEDURE 4-2

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There are a number of special screws that cut their own © Jones & BartlettIntroduction Learning, LLC © Jones & Bartlett Learning, LLC threads as they go. This is called tapping a thread. Pictured NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Locking devices used in the motorcycle industry are pri- in FIGURE 4-4A is a self-tapping screw. It is made of hard marily designed to hold things in a particular location material that cuts a mirror image of itself into the hole as or to hold things together. These devices come in many you turn it. The screw in FIGURE 4-4B is also known as a forms, and depending on the particular application, one self-tapping screw, but it is designed for cutting and holding or more types of locking© Jones devices &may Bartlett be used. Learning, They can LLCthin sheet metal, so it is often© used Jones on motorcycle & Bartlett bodies. Learning, LLC be in the form of a physicalNOT FOR fastener SALE and/or OR chemicalDISTRIBUTION NOT FOR SALE OR DISTRIBUTION adhesive. This chapter provides a description of the types of locking devices found in motorcycle design.

Locking© Jones & DevicesBartlett Learning, and Tools LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Fasteners There are many different fasteners used in motorcycle applications, including screws, bolts, studs and nuts. © Jones &Washers Bartlett and Learning,chemical compounds LLC can be used to help© Jones & Bartlett Learning, LLC NOT FORsecure SALE these OR fasteners. DISTRIBUTION NOT FOR SALE OR DISTRIBUTION A Screws Screws are generally smaller than bolts and are sometimes referred to as metal threads FIGURE 4-1 . They can © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC have a variety of heads, they’re used on smaller components, and often theirNOT thread FOR extends SALE right OR from DISTRIBUTION the tip NOT FOR SALE OR DISTRIBUTION to the head so they can hold together components of different thickness. Different screws can be tightened with a range of tools. An Allen© Jones head screw& Bartlett has a recessLearning, for an AllenLLC wrench © Jones & Bartlett Learning, LLC FIGURENOT 4-2 .FOR An Allen SALE head OR screw DISTRIBUTION is sometimes called a NOT FOR SALE OR DISTRIBUTION cap screw. It usually screws into a hole rather than a nut, and it needs tightening with an Allen wrench. A machine screw has a slot for a screwdriver B FIGURE 4-3 . Screwdrivers come in many sizes and you © Jones &should Bartlett always Learning, use the correct LLC size blade for the particular© JonesFIGURE & Bartlett 4-2 A. An Learning, Allen head screw. LLC B. Allen wrenches. NOT FORmachine SALE screwOR DISTRIBUTION slot. NOT FOR SALE OR DISTRIBUTION

FIGURE 4-1 Screws are generally smaller than bolts and are © Jones & Bartlettsometimes referred Learning, to as metal LLC threads. © JonesFIGURE & Bartlett 4-3 A machine Learning, screw. LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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© Jones & Bartlett Learning, LLC © Jones &TECHNICIAN Bartlett Learning, TIP LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Threads are cut on screws, bolts, nuts and studs and inside holes to allow components to be attached and assembled. There was a time when there were many different thread designs used throughout the world. © Jones & Bartlett Learning, LLCModern motorcycles still use© a Jonesrange of thread& Bartlett patterns, Learning, LLC NOT FOR SALE OR DISTRIBUTIONbut due to standardization, itNOT is getting FOR much SALE simpler OR DISTRIBUTION FIGURE 4-5 . Nearly all the nuts, bolts, screws and studs on a motorcycle have a V-thread cut into them. A screw jack or a clamp has square threads cut into it. The square thread is more difficult to machine and is © Jones & Bartlett Learning, LLC used mainly© Jonesin situations & Bartlettwhere rotational Learning, movement LLC ANOT FOR SALE OR DISTRIBUTION needs to NOTbe transferred FOR SALE into lateral OR movement—for DISTRIBUTION example, the screw in a vise where the rotary movement of turning the handle is translated into the lateral movement of the jaws closing. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOTBolts, FOR SALEStuds ORand DISTRIBUTION Nuts Bolts, studs and nuts are fasteners designed for heavier jobs than screws and tend to be made of metal or metal alloys. Bolts are cylindrical pieces of metal with a hex- © Jones & Bartlett Learning, LLCagonal head on one end and© aJones thread cut& Bartlettinto the shaft Learning, LLC NOT FOR SALE OR DISTRIBUTIONat the other end FIGURE 4-6NOT. They FOR are often SALE bigger OR than DISTRIBUTION screws and are used for heavier jobs. Bolts are always threaded into a nut or hole that has an identical thread cut inside. The thread acts as an inclined plane; as the bolt © Jones & Bartlett Learning, LLC is turned, it© is Jones drawn into & Bartlett or out of theLearning, matching thread.LLC Nuts are often used with bolts. A nut is a piece of BNOT FOR SALE OR DISTRIBUTION metal, usuallyNOT hexagonal, FOR SALE with ORa thread DISTRIBUTION cut through it to fit the bolt thread. The hexagonal heads for the bolt FIGURE 4-4 Self-tapping screws. and nut are designed to fit tools such as combination wrenches and sockets FIGURE 4-7 . © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

o Acme thread Square thread 29 worm thread

©P Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC P P o NOT29 FOR SALE OR DISTRIBUTION NOT FORo SALE OR DISTRIBUTION W W 29 F F D D D C C © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Standard thread shapes

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Bolt dimensions © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALEBolt OR length DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 4-6 Bolt. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Torx drivers are used for torx bolts and are often found in motorcycle engines; they may be found in places such as cylinder heads to blocks, where particular tightening © Jones & Bartlett Learning, LLCsequences are required FIGURE© Jones 4-8 . & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONThere are many different waysNOT to FOR keep theSALE nut and OR bolt DISTRIBUTION done up tightly. A self-locking or Nylock nut can have a plastic or nylon insert. Tightening the bolt squeezes it into the insert, where it resists any movement. The self-locker © Jones & Bartlett Learning, LLC is highly resistant© Jones to being & Bartlett loosened Learning,by the kind of LLC vibra- tion that engines and motorcycles experience FIGURE 4-9 . NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Tightening this style of nut distorts the insert, so it provides its locking effect only the first time you use it. If you remove the nut, it should be replaced with a new one. FIGURE 4-7 Bolts usually have hexagonal heads. A castellated nut has slots like towers on a castle © Jones & Bartlett Learning, LLC © JonesFIGURE & 4-10 Bartlett. When Learning, it is screwed LLC onto a bolt that has NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 4-8 Torx bolts are often found in motorcycle applications; they may be found in places such as cylinder heads FIGURE 4-9 A self-locking nut is highly resistant to being © Jones & Bartlettto blocks, where Learning, particular tightening LLC sequences are required. © Jonesloosened & Bartlett by vibrations. Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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© Jones &been Bartlett drilled inLearning, the right spot, LLC a split pin can be passed© Jones & Bartlett Learning, LLC NOT FORthrough SALE themOR DISTRIBUTIONboth and then spread open to lock theNOT FOR SALE OR DISTRIBUTION nut in place. Castellated nuts are used where scheduled maintenance requires inspection and adjustments to take place, for items such as front wheel bearings. A speed nut is not© as Jones strong as& theBartlett other types,Learning, but LLCB © Jones & Bartlett Learning, LLC it can be a fast and convenientNOT FOR way SALE to secure OR DISTRIBUTIONa screw NOT FOR SALE OR DISTRIBUTION FIGURE 4-11 . Once the speed nut is started, it does not need to be held. These are often used in places like body component fixings. Some bolts and nuts need washers. Washers can be made© from Jones a number & Bartlett of materials Learning, depending LLC on their © Jones & Bartlett Learning, LLC application,NOT FOR including SALE aluminum, OR DISTRIBUTION copper, fiber and steel. NOT FOR SALE OR DISTRIBUTION Here are some brief descriptions of the more common washers FIGURE 4-12 : ■■ Flat washers spread the load of a bolt head or a nut © Jones & Bartlettas it is tightened Learning, and distributeLLC it over a greater area.© Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION C

NOT FOR SALE OR DISTRIBUTION D NOT FOR SALE OR DISTRIBUTION

FIGURE 4-12 Types of washers. A. Flat washer. B. Spring washer. C. Serrated edge shake-proof washers. © Jones & BartlettFIGURE 4-11 Learning, Speed nut. LLC © JonesD. Tab& washer.Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 111 3/12/14 9:24 PM 112 CHAPTER 4 Identifying Locking Devices

This protects the surface underneath from being © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC marked by the nut or head as it turns and tightens NOT FOR SALEdown. OR Flat DISTRIBUTION washers should always be used to protectNOT FOR SALE OR DISTRIBUTION aluminum alloy. ■■ A spring washer compresses as the nut tightens, and the nut is spring loaded against this surface, which makes it unlikely© Jones to work & Bartlett loose. The Learning, ends of LLC © Jones & Bartlett Learning, LLC the spring washerNOT also FOR bite into SALE the metal.OR DISTRIBUTION Spring NOT FOR SALE OR DISTRIBUTION washers are used more for bolts and nuts. ■■ Screws mostly rely on smaller serrated edge shake- proof washers. The external ones have teeth on ©the Jones outside, & and Bartlett the internal Learning, ones have LLC teeth on the © Jones & Bartlett Learning, LLC NOTinside; FOR one type SALE has both.OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ■■ Tab washers get their name from these extensions. FIGURE 4-14 Bolts and nuts are often marked to indicate After the nut or bolt has been tightened, they remain how much torque can be safely applied to them. Markings exposed and are folded up to grip the flats and using the metric system are shown here. © Jones & Bartlettprevent Learning,movement. LLC © Jones & Bartlett Learning, LLC NOT FOR SALEOften, theOR thread DISTRIBUTION on a stud is only as long as it needsNOT FOR SALE OR DISTRIBUTION to be to tighten onto the nut or into the threaded hole. Some special versions have both a left- and right-hand thread pitch, length and grade. The diameter is meas- thread on them. A stud is like two bolts in one; for ured across the outside of the threads; it is measured instance, an exhaust ©manifold Jones on & theBartlett cylinder Learning, head is LLCin fractions of an inch for standard-type© Jones & Bartlettfasteners, andLearning, LLC millimeters for metric-type fasteners. A 3/8 (9.5-mm) normally located and NOTheld by FOR studs SALE and nuts. OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION A stud does not have a fixed hexagonal head; rather, it bolt has a thread diameter of 3/8 (9.5 mm); 3/8 is not has a thread cut on each end FIGURE 4-13 . It is threaded the size of the bolt head. into one part, where it stays. The mating part is then The metric system uses numbers stamped on the heads slipped over it and a nut is threaded onto the end of of metric bolts and on the face of metric nuts FIGURE 4-14 . the stud© Jones to secure & the Bartlett part. Studs Learning, are commonly LLC used to Even studs© have Jones a marking & Bartlett system to Learning, make sure they LLC are attachNOT a throttle FOR body SALE to the OR intake DISTRIBUTION manifold. Studs can not over-stressedNOT FORwhen youSALE tighten OR them. DISTRIBUTION The numbers have different threads on each end. indicate the tensile strength of the bolt. Tensile strength Bolts, nuts and studs can have either standard or metric refers to how much tension it can withstand before it threads. They are designated by their thread diameter, breaks. The number does not mean the size of the bolt. Note: The distance between flats on the bolt or nut heads © Jones & Bartlett Learning, LLC © Jonesgenerally & Bartlett indicates Learning,wrench size toLLC be used. NOT FOR SALE OR DISTRIBUTION NOT FORThe imperialSALE OR system DISTRIBUTION also uses a marking system to indicate tensile strength, as shown in FIGURE 4-15 . This is a grade 5 bolt, and can be tightened to specific torque as specified by the manufacturer. The dots on this nut, © Jones & Bartlett Learning, LLCalso a grade 5, give similar information.© Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONThe coarseness of any threadNOT is called FOR its SALE thread OR pitch DISTRIBUTION. In the standard system, bolts, studs and nuts are measured in threads per inch (tpi). To determine the tpi, simply count the number of threads there are in 1 inch. Each bolt diameter in the standard system can have one of © Jones & Bartlett Learning, LLC two thread© pitches, Jones coarse & Bartlett (UNC) Learning,or fine (UNF). LLC For NOT FOR SALE OR DISTRIBUTION example, aNOT 3/8-16 FOR is coarse, SALE while OR aDISTRIBUTION 3/8-24 is fine. In the metric system, the thread pitch is measured by the distance between the peaks of the threads in millimeters FIGURE 4-13 A stud has threads on each end. FIGURE 4-16 . Each bolt diameter in the metric system can © Jones & Bartlett Learning, LLC © Joneshave up & toBartlett four thread Learning, pitches. Metric LLC threads, designated NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 112 3/12/14 9:24 PM CHAPTER 4 Identifying Locking Devices 113

with a capital M, are rated according to their outer diam- © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC eter and their pitch. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION The length of a bolt is fairly straightforward. It is measured from the end of the bolt to the bottom of the head and is listed in inches or millimeters. The grade of a fastener relates to its strength. The higher the grade © Jones & Bartlett Learning, LLCnumber, the higher the tensile© Jonesstrength. & Tensile Bartlett strength Learning, LLC NOT FOR SALE OR DISTRIBUTIONfor fasteners is generally listedNOT in pounds FOR perSALE square OR inch DISTRIBUTION of bolt shaft area. Tensile strength for metric fasteners is generally listed in megapascals, or MPa, of bolt shaft area. A metric bolt marked on the head as 10.9, for example, © Jones & Bartlett Learning, LLC would have© anJones approximate & Bartlett yield Learning, strength of 90%LLC of 1,000 MPa. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 4-15 Tensile strength markings using the imperial system—Grade 5 bolt. TECHNICIAN TIP

© Jones & Bartlett Learning, LLC © JonesWhile & USBartlett and some Learning, other manufacturers LLC use the NOT FOR SALE OR DISTRIBUTION NOT FORimperial SALE system OR of inch-pounds,DISTRIBUTION the global version of metric is called the International System of Units, or SI. No. of threads per inch The metric system has produced some competing 1 Inch classifications for fasteners. For example, metric hex © Jones & Bartlett Learning, LLCcap screws may have three© different Jones standards: & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 1. DIN 931 (DIN 933 fully threaded) Diameter of bolt in inches 2. ISO 4014 (ISO 4017 fully threaded) 3. ANSI/ASME B18.2.3.1M © Jones & Bartlett Learning, LLC These three© Jones standards & are Bartlett interchangeable, Learning, differing LLC NOT FOR SALE OR DISTRIBUTION primarily NOTin the widthFOR across SALE the OR flat DISTRIBUTIONdimensions. A

© Jones & Bartlett Learning,Distance between LLC © Jones &TECHNICIAN Bartlett Learning, TIP LLC the peaks in millimeters NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Many motorcycle bolts and nuts need to be tightened to a specified level—tight enough to hold components together but not so tight that the component or the Diameter of fastener could fail. This level of tightness is called © Jones & Bartlettbolt Learning, in LLCthe torque specification. Bolts© Jonesand nuts are& Bartlett often Learning, LLC millimeters NOT FOR SALE OR DISTRIBUTIONmarked with grades to tell youNOT their FOR strength, SALE which OR DISTRIBUTION determines how much torque can safely be applied to them. For example, a grade 8 bolt is stronger than a grade 5 bolt and can be tightened to a higher B torque. The specific torque required for every bolt © Jones & Bartlett Learning, LLC on the motorcycle© Jones should & Bartlett always be Learning, obtained from LLC NOT FOR SALE OR DISTRIBUTION the manufacturer’sNOT FOR technical SALE information OR DISTRIBUTION system. FIGURE 4-16 A. In the standard system, the thread pitch is Once bolts are tightened, there are different ways to measured in threads per inch (tpi). B. In the metric system, the ensure they stay tight. For example, a locking washer, thread pitch is measured by the distance between the peaks of a locking chemical compound or a nylon locking device the threads in millimeters. built into the nut may be used. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Fasteners and Torque NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Fasteners are designed to secure parts that are under various tension and shear stresses. The nature of the stresses placed on parts and fasteners depends on their use and location. For example, head bolts withstand © Jones & Bartlett Learning, LLCtension stresses by clamping ©the Jones head gasket & Bartlett between Learning,the LLC NOT FOR SALE OR DISTRIBUTIONcylinder head and the block. NOTThe bolts FOR must SALE withstand OR the DISTRIBUTION very high combustion pressures trying to push the head off the engine block in order to leak past the head gasket. An example of fasteners withstanding shear stresses is © Jones & Bartlett Learning, LLC wheel studs© and Jones wheel & nuts Bartlett on a quad. Learning, They clamp LLC the NOT FOR SALE OR DISTRIBUTION wheel assemblyNOT to FOR the suspension SALE OR system, DISTRIBUTION and the weight of the quad tries to shear the lug studs. If this were to happen, the wheel would fall off the quad, leading to FIGURE 4-17 Applying a chemical compound such as Loctite an accident. to the threads helps prevent fasteners from loosening. To accomplish their job, fasteners come in a variety © Jones & Bartlett Learning, LLC © Jonesof diameters & Bartlett and Learning, hardnesses, LLC which are defined in NOT FOR SALE OR DISTRIBUTION NOTtensile FOR strengthSALE OR grades. DISTRIBUTION Fasteners with screw threads Chemical Compounds are designed to be tightened to a specific torque depending on the job at hand, the tensile strength Chemical compounds (such as Loctite) help prevent or hardness of the material they are made from, their fasteners from loosening FIGURE 4-17 . They are applied size and the thread pitch. If a fastener is overtight- to one thread, and then© Jones the other & Bartlettis screwed Learning, onto it. LLC © Jones & Bartlett Learning, LLC ened, it could become damaged or could break. If it is This creates a strong NOTbond betweenFOR SALE them, ORbut oneDISTRIBUTION that NOT FOR SALE OR DISTRIBUTION undertightened, it could work loose over time. Torque stays plastic, so in the future they can be separated with is a way of defining how much a fastener should be a wrench if necessary. tightened. Some metals react with each other and bind together— for instance,© Jones spark & Bartlett plugs when Learning, they are inLLC aluminum Torque Charts© Jones & Bartlett Learning, LLC cylinderNOT heads. FOR An SALE anti-seize OR compound DISTRIBUTION neutralizes the NOT FOR SALE OR DISTRIBUTION chemical reaction that can make this happen and prevents Torque specifications for bolts and nuts in motorcy- threads and fasteners from sticking together FIGURE 4-18 . cles will usually be contained within workshop man- uals. Bolt, nut and stud manufacturers also produce torque charts, which contain all the information you © Jones & Bartlett Learning, LLC © Jonesneed &to Bartlettdetermine Learning, the maximum LLC torque of bolts or NOT FOR SALE OR DISTRIBUTION NOTnuts FOR FIGURE SALE 4-19 OR. For DISTRIBUTION example, most charts include the bolt diameter, threads per inch (or mm), grade and maximum torque setting for both dry and lubricated bolts and nuts. A lubricated bolt and nut will reach maximum torque value at a lower setting. In practice, © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC most torque specifications call for the nuts and bolts NOT FOR SALE OR DISTRIBUTIONto have dry threads prior toNOT tightening. FOR ThereSALE are OR some DISTRIBUTION exceptions, so close examination of the torque specification chart is critical.

© Jones & Bartlett Learning, LLC Friction© Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION Friction isNOT a force FOR that SALE resists OR the DISTRIBUTIONmovement of one surface over another. It can be desirable in some FIGURE 4-18 Applying an anti-seize compound prevents cases and not desirable in others. For instance, lock- threads and fasteners from sticking together. ing devices rely on friction to hold them together © Jones & Bartlett Learning, LLC © Jonesand in & place,Bartlett whereas Learning, an engine LLC requires the least NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALEIn the OR absence DISTRIBUTION of torque specifications the values below can be used as a guide to the maximum safe torque for a specific diameter/grade of fastener. The torque specification is for clean dry threads, if the threads are oiled reduce the torque by 10%.

Bolt Grade Marking © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Bolt Diameter NOT FOR4.6 SALE OR DISTRIBUTION4.8 8.8 10.9NOT FOR SALE12.9 OR DISTRIBUTION Maximum Torque Maximum Torque Maximum Torque Maximum Torque Maximum Torque lb ft Nm lb ft Nm lb ft Nm lb ft Nm lb ft Nm

M4 0.8 1.1 1 1.5 2 3 3 4.5 4 5 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOTM5 FOR SALE1.5 OR DISTRIBUTION2.5 2 3 4.5 NOT6 FOR6.5 SALE9 OR DISTRIBUTION7.5 10

M6 3 4 4 5.5 7.5 10 1.1 15 13 18

M8 7 9.5 10 13 18 25 26 35 33 45

M14 37 50 55 75 103 140 151 205 177 240

M16 © Jones59 &80 Bartlett85 Learning,115 LLC159 215 232 ©315 Jones 273& Bartlett370 Learning, LLC

M18 NOT81 FOR 110SALE OR118 DISTRIBUTION160 225 305 321 NOT435 FOR376 SALE510 OR DISTRIBUTION

M20 118 160 166 225 321 435 457 620 535 725

M22 159 215 225 305 435 590 620 840 726 985 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 4-19 Torque specification chart.

© Jones &friction Bartlett possible Learning, and relies LLC on the lubrication system© Jonestires do & notBartlett slide easily Learning, when you LLC apply the brakes or NOT FORto SALE prevent OR friction. DISTRIBUTION NOTturn FOR into SALE a corner. OR DISTRIBUTION Friction is caused by surface rough spots that lock together. These spots can be microscopically small, Locking Device which is why even surfaces that seem to be smooth can experience friction. Friction© Jones can &be Bartlett reduced butLearning, never LLCMeasuring Tools© Jones & Bartlett Learning, LLC eliminated. NOT FOR SALE OR DISTRIBUTIONTorque Wrenches NOT FOR SALE OR DISTRIBUTION Friction is always measured for pairs of surfaces, using what is called a coefficient of friction. A torque wrench is also known as a tension wrench A low coefficient of friction for a pair of surfaces means FIGURE 4-20 . It is used to tighten fasteners to a prede- they can move easily over each other. Ice and metal have termined torque. It is designed to tighten bolts and nuts a low© coefficient Jones & of Bartlett friction, soLearning, metal ice skates LLC slide eas- using the drive© Jones on the & end, Bartlett which Learning,fits with any LLC socket ily onNOT ice. FOR SALE OR DISTRIBUTION and accessoryNOT of FORthe same SALE drive OR size DISTRIBUTION found in an ordi- A high coefficient of friction for a pair of surfaces nary socket set. Although manufacturers do not specify means they cannot move easily over each other. Rubber torque settings for every nut and bolt, it is important to tires and dry road surfaces have a high coefficient of follow the specifications when they do. For example, © Jones &friction, Bartlett so they Learning, tend to gripLLC each other. That means© Jonesmanufacturers & Bartlett specify Learning, a torque forLLC cylinder head bolts. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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placed at the end of a 1-inch-long lever. Also note that © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC 1 lb-ft equals 12 in-lb. A newton meter is described as NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION the amount of twisting force applied to a shaft by a per- pendicular lever 1 meter long with a force of 1 newton applied to the outer end. A torque value of 100 Nm will be the same as applying a 100-newton force to the end © Jones & Bartlett Learning, LLCof a 1-meter-long lever. (One© lb-ft Jones is equal & toBartlett 1.35 Nm.) Learning, LLC NOT FOR SALE OR DISTRIBUTIONTorque wrenches come inNOT various FOR types: SALE beam OR style, DISTRIBUTION clicker, dial and electronic FIGURE 4-22 . The simplest and least expensive is the beam-style torque wrench. It uses a spring steel beam that flexes under tension. A smaller © Jones & Bartlett Learning, LLC fixed rod then© Jones indicates & theBartlett amount Learning, of torque on LLC a scale mounted to the bar. The amount of deflection of the bar NOT FOR SALE OR DISTRIBUTION coincides withNOT the FOR amount SALE of torque OR DISTRIBUTION on the scale. One drawback of this design is that you have to be positioned FIGURE 4-20 The torque wrench has an adjustable handle, directly above the scale so you can read it accurately. which allows technicians to adjust to the correct torque specification for the job. That can be a problem when working in confined spaces. © Jones & Bartlett Learning, LLC © JonesThe & clicker-style Bartlett Learning, torque wrench LLC uses an adjustable NOT FOR SALE OR DISTRIBUTION NOTclutch FOR insideSALE that OR slips DISTRIBUTION (clicks) when the preset torque is reached. You can set it for a particular torque on the The torque specified will ensure that the bolt provides handle. As the bolt is tightened, once the preset torque is the proper clamping pressure and will not come loose, reached, the torque wrench will click. This makes it espe- but will not be so tight as to risk breaking the bolt or cially handy in situations where the scale of a beam-style © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC stripping the threads FIGURE 4-21 . torque wrench cannot be read. The higher the torque, The torque value willNOT be specified FOR SALE in foot-pounds OR DISTRIBUTION (lb-ft), the louder the click; the lowerNOT the torque,FOR SALE the quieter OR the DISTRIBUTION inch-pounds (in-lb), or newton meters (Nm). The torque click. Be careful when using this style of torque wrench, value is the amount of twisting force applied to a fastener especially at lower torque settings. It is easy to miss the by the torque wrench. A foot-pound is described as the click and overtighten, break or strip the bolt. Once the amount© Jones of twisting & Bartlettforce applied Learning, to a shaft LLCby a perpen- torque wrench© Jones clicks, stop& Bartlett turning it,Learning, as it will continue LLC dicularNOT lever FOR 1 foot SALE long with OR a weightDISTRIBUTION of 1 pound placed to tighten theNOT fastener FOR if SALEyou turn OR it past DISTRIBUTION the click point. on the outer end. A torque value of 100 lb-ft will be the The dial torque wrench turns a dial that indicates the torque same as a 100-lb weight placed at the end of a 1-foot-long based on the torque being applied. Like the beam-style torque lever. A torque value of an inch-pound will be 1 pound wrench, you have to be able to see the dial to know how much torque is being applied. Many dial torque wrenches © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 4-21 The torque wrench is fitted over the wheel © Jones & Bartlettlocking nuts andLearning, tightened to theLLC specified torque. © JonesFIGURE & Bartlett 4-22 Torque Learning, wrench. LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 116 3/12/14 9:24 PM CHAPTER 4 Identifying Locking Devices 117

have a movable indicator that is moved by the dial and stays the fastener increases. Tightening a rusty fastener to a par- © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC at the highest reading. That way, you can double-check the ticular torque will not provide as much clamping force as NOT FOR SALE OR DISTRIBUTION NOT FORtorque SALE achieved OR DISTRIBUTION once the torque wrench is released. Once a smooth fastener torqued the same amount. All threads the proper torque is reached, the indicator can be moved must be clean before tightening the fastener to a specified back to zero for the next fastener being torqued. torque. This also brings up the question of whether threads The digital torque wrench usually uses a spring steel bar should be lubricated. In most motorcycle cases, the torque with an electronic strain© Jonesgauge to &measure Bartlett the amountLearning, of LLCvalues specified are for dry,© non-lubricatedJones & Bartlett threads, Learning, but LLC torque being applied. TheNOT torque FOR wrench SALE can beOR preset DISTRIBUTION to the always check the manufacturer’sNOT specifications. FOR SALE OR DISTRIBUTION desired torque. It will then display the torque as the fastener When bolts are tightened, they are also stretched. As is being tightened. When it reaches the preset torque, it will long as they are not tightened too much, they will return usually give an audible signal, such as a beep. This makes to their original length when loosened. This is called it useful© Jonesin situations & Bartlett where a scale Learning, or dial cannot LLC be read. elasticity. ©If theyJones continue & Bartlett to be tightened Learning, and LLCstretch Torque wrenches fall out of calibration over time or beyond their point of elasticity, they will not return to if theyNOT are not FOR used SALE properly, OR so DISTRIBUTION they should be checked their originalNOT length FOR when SALE loosened. OR DISTRIBUTION This is called the and calibrated annually. This can be performed in the yield point. Torque-to-yield (TTY) means that a fastener workshop if the proper calibration equipment is available, is torqued to, or just beyond, its yield point. or the torque wrench can be sent to a qualified service With the changes in engine metallurgy that manufactur- © Jones ¢er. Bartlett Most Learning,quality torque LLC wrench manufacturers pro©- Jonesers are & using Bartlett in modern Learning, motorcycles, LLC bolt technology has NOT FORvide SALE a recalibration OR DISTRIBUTION service for their customers. NOThad FOR to change SALE as OR well. DISTRIBUTION To help prevent bolts from loosening over time and to maintain an adequate clamping force Using a Torque Wrench and when the engine is both cold and hot, manufacturers have a Torque Angle Gauge adopted “stretch” or torque-to-yield (TTY) bolts. TTY bolts are designed to provide a consistent clamping force To help ensure that the© proper Jones amount & Bartlett of torque Learning, gets from LLC © Jones & Bartlett Learning, LLC the torque wrench to the bolt, support the head of the torque when torqued to their yield point or just beyond. The NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION wrench with one hand FIGURE 4-23 . When using a torque challenge is that the torque does not increase very much, wrench, it is best not to use extensions. Extensions make or at all, once yield is reached, so using a torque wrench by it harder to support the head, which can end up absorbing itself will not indicate the point at which the manufacturer some of the torque. If possible, use a deep socket instead. wants the bolt tightened. Consequently, TTY bolts generally Torque© Jones is not always& Bartlett the best Learning, method of LLCensuring that require a new© torqueingJones & procedure Bartlett called Learning, torque angle. LLC It is a boltNOT is tightened FOR SALE enough OR to give DISTRIBUTION the proper amount of important toNOT note that,FOR in SALE virtually OR all cases, DISTRIBUTION TTY bolts can- clamping force. If the threads are rusty, rough or damaged not be reused because they have been stretched into their in any way, the amount of twisting force required to tighten yield zone and would very likely fail if re-torqued. Always check the manufacturer’s specifications when doing this as some manufacturers say that the bolt must be changed © Jones & Bartlett Learning, LLC © Jonesonce a& maximum Bartlett length Learning, has been LLC reached. NOT FOR SALE OR DISTRIBUTION NOT FORTorque SALE angle OR is considered DISTRIBUTION a more precise method to tighten TTY bolts and is essentially a multistep process. Bolts are first torqued in the required pattern using a standard torque wrench to a required moderate torque © Jones & Bartlett Learning, LLCsetting FIGURE 4-24 . They are© thenJones further & Bartlett tightened Learning, an LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Safety

For your safety: © Jones & Bartlett Learning, LLC ■■ Refer to© theJones manufacturer’s & Bartlett specifications Learning, when LLC NOT FOR SALE OR DISTRIBUTION tighteningNOT fasteners. FOR SALE OR DISTRIBUTION ■■ Return the torque wrench to its lowest setting FIGURE 4-23 Ensure the proper amount of torque gets when finished. from the torque wrench to the bolt by supporting the head of ■■ If replacing a fastener, make sure it has the correct © Jones & Bartlettthe torque wrench Learning, with one hand.LLC © Jonestensile & Bartlett value for Learning, the task it will LLC perform. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 117 3/12/14 9:24 PM 118 CHAPTER 4 Identifying Locking Devices

To use a torque wrench and torque angle gauge, follow © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC the guidelines in PROCEDURE 4-1 . NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Helical Inserts © Jones & Bartlett Learning, LLCNo matter how strong a bolt© is, Jones it can break. & Bartlett There are Learning, a LLC NOT FOR SALE OR DISTRIBUTIONnumber of techniques usedNOT to remove FOR broken SALE bolts OR and DISTRIBUTION repair threads. Those techniques will be demonstrated later in this series. One of the tools used to repair damaged bolt holes are helical inserts, more commonly known by their trademark Helicoil FIGURE 4-26 . Helicoils are © Jones & Bartlett Learning, LLC made of coiled© Jones wire and & areBartlett inserted Learning, into a tapped LLC hole NOT FOR SALE OR DISTRIBUTION that is largerNOT than FOR the desiredSALE hole.OR DISTRIBUTIONHelicoils are self- anchoring, and special tools are required to install them. FIGURE 4-24 Torque sequence. Once in place, a new bolt or spark plug is threaded into the helicoil insert. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORadditional SALE OR specified DISTRIBUTION angle (torque angle) using an angleNOT FOR SALE OR DISTRIBUTION gauge, thus providing further tightening to tighten the Locking Pins and Keys bolt to, or beyond, its yield point. In some cases, after A split pin is used to secure other fasteners, typically torqueing, the manufacturer first wants all of the bolts castellated nuts FIGURE 4-27 . Split pins are often made to be turned to an initial© Jonesangle, and & thenBartlett turned Learning, an addi- LLCof soft metal, making them© easy Jones to install & Bartlett or remove. Learning, LLC tional angle FIGURE 4-25NOT . In otherFOR cases, SALE the manufacturerOR DISTRIBUTION They should never be usedNOT more FOR than once,SALE and OR they DISTRIBUTION wants all of the bolts torqued in a particular sequence, should not be used in applications where there are then de-torqued in a particular sequence, then re-torqued strong shearing forces at play. Split pins are also used once again in a particular sequence and finally tightened to keep other components, such as washers, from com- an additional specified angle. You must therefore always ing off shafts. check© the Jones manufacturer’s & Bartlett specifications Learning, andLLC procedure To remove© andJones install & splitBartlett pins, followLearning, the guidelines LLC beforeNOT torqueing FOR TTYSALE bolts. OR DISTRIBUTION in PROCEDURENOT 4-2 FOR . SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 118 3/12/14 9:24 PM CHAPTER 4 Identifying Locking Devices 119

© Jones & Bartlett Learning, LLC 1 Identify the stretch bolt either© Jones through the& Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONmanufacturer’s specificationsNOT or, inFOR some SALE cases, stretch OR DISTRIBUTION bolts themselves have a specific marking on the head of the bolt. In addition, the diameter of the shank of the bolt is thinner than the threaded diameter.

2 Check the specifications. Determine the correct © Jones & Bartlett Learning, LLC torque ©value Jones and sequence & Bartlett for the boltsLearning, or fastener LLC NOT FOR SALE OR DISTRIBUTION you areNOT using. FORThis will SALE be in foot-pounds OR DISTRIBUTION or newton meters (Nm). Also check the torque angle specifications for the bolt or fastener, and whether the procedure is one step or more than one step.

© Jones & Bartlett Learning, LLC © Jones 3 Tighten & Bartlett the bolt toLearning, the specified LLC torque. If the NOT FOR SALE OR DISTRIBUTION NOT FORcomponent SALE requiresOR DISTRIBUTION multiple bolts or fasteners, make sure to tighten them all to the same torque value in the sequence and follow the steps that are specified by the manufacturer. Some torqueing procedures could call for a number of steps to complete the torqueing process. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC For example, motorcycle specifications as follows: NOT FOR SALE OR DISTRIBUTIONa. Step 1: Torque bolts toNOT 29.5 foot-pounds, FOR SALE or OR DISTRIBUTION 40 newton meters (Nm). b. Step 2: Torque bolts to 44 foot-pounds, or 60 newton meters (Nm). © Jones & Bartlett Learning, LLC c. Step© 3: Jones Finally, tighten & Bartlett the bolt a Learning,further 90 degrees. LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

1 Ensure you have the correct size of split pin for the relevant hole size.

© Jones & Bartlett Learning, LLC 2 Use an appropriate pair of© pliers Jones to straighten & Bartlett the legs Learning, LLC of the split pin. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 4 Grip the pin head and pull it out of the nut or bolt. 4 Make the required repair/adjustment and reassemble and adjust accordingly. © Jones & Bartlett Learning, LLC 5 Insert the© Jonesnew pin, legs& Bartlett first, as far Learning,as it will go. LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 6 Bend the legs back and cut them to the required size if necessary.

056754_CH04_p106-125.indd 119 3/12/14 9:24 PM 120 CHAPTER 4 Identifying Locking Devices

© Jones & Bartlett Learning, LLC © JonesRawl & pinsBartlett FIGURE Learning, 4-28 are often LLC used to hold components on rotating shafts. They are a type of shear pin, NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION used when excessive force is used to avoid further damage to a component. They are normally made from a spring-type steel. © Jones & Bartlett Learning, LLCLocking Keys © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONKeys are used to prevent theNOT free FOR rotation SALE of gears OR DISTRIBUTIONor pulleys on a shaft FIGURE 4-29 . Keys come in various shapes depending on their use: ■■ Parallel keys, for example, can be used to secure © Jones & Bartlett Learning, LLC a gear© wheel Jones on its & shaftBartlett FIGURE Learning, 4-30 . LLC NOT FOR SALE OR DISTRIBUTION ■■ TaperNOT keys FORare used SALE to anchor OR DISTRIBUTIONa pulley to a shaft or a disc to a driving shaft FIGURE 4-31 . FIGURE 4-27 Split pins. ■■ A feather key is usually attached to levers that have to slide along a shaft to allow engagement of a part © Jones & Bartlett Learning, LLC © Jones FIGURE& Bartlett 4-32 . ALearning, feather key LLC is an extra component NOT FORLocking SALE OR Pins DISTRIBUTION NOT FORused SALE with ORa shaft-to-collar DISTRIBUTION connection. The con- Dowel pins are used to keep components in place where nection is positive fitting and serves to transmit shearing forces are high. For example, they are used in torques and revs, for example, on the driveshaft of high-pressure pumps to keep valve plates anchored in a belt pulley. position. Pins should ©never Jones be directly & Bartlett struck byLearning, a ham- LLC■■ Gibb-head keys are designed© Jones to be & pulled Bartlett out easLearning,- LLC mer; a pin punch shouldNOT be FOR used instead.SALE OR DISTRIBUTIONily and are used whenNOT a gear FOR or a pulley SALE has OR to beDISTRIBUTION Taper pins are used to position parts on a shaft, for attached to a shaft FIGURE 4-33 . example gears, pulleys and collars. They are steel rods with one end having a slightly larger diameter than the other. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Keyway

FIGURE 4-28 Rawl pins. FIGURE 4-29 Locking keys. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 120 3/12/14 9:24 PM CHAPTER 4 Identifying Locking Devices 121

Peg Feather Key FIGURE 4-30 Parallel keys. FIGURE 4-32 Peg feather key.

FIGURE 4-31 Taper key. FIGURE 4-33 Gibb-head key. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 121 3/12/14 9:24 PM 122 CHAPTER 4 Identifying Locking Devices

© Jones & BartlettVocabulary Learning, BuilderLLC and Review© Jones Questions & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Vocabulary Builder imperial system Bolts, nuts and studs can have either imperial or metric threads. They are designated by their Allen head screw Sometimes called a cap screw, it has a © Jones & Bartlett Learning, LLCthread diameter, thread pitch,© lengthJones and & grade. Bartlett Imperial Learning, LLC hexagonal recess in the head which fits an Allen wrench. measures are in feet, inches and fractions of inches. The NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION This type of screw usually anchors components in a pre- United States uses the imperial system, but most countries drilled hole. use the metric system. anti-seize compound Neutralizes a chemical reaction machine screw A screw with a slot for screwdrivers. that can prevent threads and fasteners from sticking together© Jones and freeze & Bartlett spark plugs Learning, in place inLLC aluminum nut A fastener© Jones with & a hexagonalBartlett Learning, head and internalLLC threads for screwing on bolts. cylinderNOT blocks. FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION bolt A type of threaded fastener with a thread on one Nylock nut Keeps the nut and bolt done up tightly; can end and a hexagonal head on the other. have a plastic or nylon insert. Tightening the bolt squeezes it into the insert, where it resists any movement. The castellated nut A nut with slots, similar to towers on a self-locker is highly resistant to being loosened. © Jones &castle, Bartlett that is Learning,used with split LLC pins; it is used primarily to© Jones & Bartlett Learning, LLC secure wheel bearings. parallel keys Used to prevent the free rotation of gears NOT FOR SALE OR DISTRIBUTION NOTor FOR pulleys SALE on a ORshaft DISTRIBUTION and can be used to secure a gear chemical compound Helps prevent fasteners from loos- wheel on its shaft. ening; it is applied to one thread, then the other fastener is screwed onto it. This creates a strong bond between rawl pins Often used to hold components on rotating shafts. They are a type of shear pin, used when them, but one that stays© plastic,Jones so & they Bartlett can be Learning,separated LLC © Jones & Bartlett Learning, LLC by a wrench. excessive force is used to avoid further damage to a NOT FOR SALE OR DISTRIBUTIONcomponent. NOT FOR SALE OR DISTRIBUTION dowel pins Used to keep components in place where shearing forces are high, such as valve plates on high- screws Usually smaller than bolts and are sometimes pressure pumps. referred to as metal threads. They can have a variety of heads, and are used on smaller components. The thread elasticity The amount of stretch or give a material has. © Jones & Bartlett Learning, LLC often extends© Jonesfrom the & tip Bartlett to the head Learning, so they can LLC hold fastenersNOT DevicesFOR SALE that securely OR DISTRIBUTION hold items together, such together componentsNOT FOR of SALE variable OR thickness. DISTRIBUTION as screws, cotter pins, rivets and bolts. self-tapping screw A screw that cuts down its own feather key Used to prevent the free rotation of gears thread as it goes. It is made of hard material that cuts a or pulleys on a shaft; usually attached to levers that have mirror image of itself into the hole as you turn it. to slide along a shaft to allow engagement of a part. The serrated edge shake-proof washer A washer that is © Jones &connection Bartlett is Learning, a positive fittingLLC and serves to transmit© Jones & Bartlett Learning, LLC used to anchor smaller screws. NOT FORtorques SALE and OR revs—for DISTRIBUTION example, on the driveshaft of NOTa FOR SALE OR DISTRIBUTION belt pulley. shear stress The form of stress that tends to produce cutting rather than stretching or bending. flat washers Spread the load of a bolt head or a nut as it is tightened and distribute it over a greater area. They speed nut A nut usually made of thin metal; it does not are particularly useful© in Jones protecting & Bartlettaluminum Learning, alloy. LLCneed to be held when started© butJones it is not& Bartlettas strong asLearning, a LLC conventional nut. A fast and convenient way to secure friction A force that resistsNOT theFOR movement SALE ofOR one DISTRIBUTION surface NOT FOR SALE OR DISTRIBUTION a screw. over another, caused by surface rough spots that lock together. Kinetic friction is resistance to motion when one spring washer A washer that compresses as the nut surface moves over another. Static friction is resistance tightens; the nut is spring loaded against this surface, which makes it unlikely to work loose. The ends of the to motion© Jones between & Bartlett two surfaces Learning, that are LLCnot moving. © Jones & Bartlett Learning, LLC spring washer also bite into the metal. FrictionNOT is alwaysFOR SALEmeasured OR for DISTRIBUTION pairs of surfaces, using NOT FOR SALE OR DISTRIBUTION a coefficient of friction. square thread A thread type with square shoulders used Gibb-head key Used to prevent the free rotation of gears or to translate rotational to lateral movement. pulleys on a shaft; designed to be pulled out easily and are stud A type of threaded fastener with a thread cut on used when a gear or a pulley has to be attached to a shaft. each end, as opposed to having a bolt head on one end. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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tab washer A washer that gets its name from the torque angle A method of tightening bolts or nuts based © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC small tabs that are folded back to secure the washer. on angles of rotation. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION After the nut or bolt has been tightened, they remain torque specification Describes the amount of twisting exposed and are folded up to grip the flats and prevent force allowable for a fastener or a specification showing movement. the twisting force from an engine crankshaft; supplied taper key Used to prevent the free rotation of gears or by manufacturers. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC pulleys on a shaft; used to anchor a pulley to a shaft or torque-to-yield A method of tightening bolts close to a disc to a driving shaft.NOT FOR SALE OR DISTRIBUTIONtheir yield point or the pointNOT at which FOR they SALE will not OR return DISTRIBUTION taper pins Used to position parts on a shaft, for example to their original length. gears, pulleys and collars. torque-to-yield (TTY) bolts Bolts that are tightened tensile strength In reference to fasteners, the amount using the torque-to-yield method. of force© Jonesit takes before& Bartlett a fastener Learning, breaks. LLC torque wrench© Jones A tool & used Bartlett to measure Learning, the rotational LLC or threadNOT pitch FOR The SALE coarseness OR orDISTRIBUTION fineness of a thread as twisting forceNOT applied FOR to SALE fasteners. OR DISTRIBUTION measured by either the threads per inch or the distance torx bolt Often found in motorcycle engines in places from the peak of one thread to the next. Metric fasteners such as cylinder heads to blocks, where particular tight- are measured in millimeters. ening sequences are required. © Jones &torque Bartlett The amountLearning, of twisting LLC force applied in a turning© Jonesyield &point Bartlett The point Learning, at which LLC a bolt is stretched so NOT FORapplication, SALE OR usually DISTRIBUTION measured in foot-pounds or newtonNOT hard FOR that SALE it fails; OR it isDISTRIBUTION measured in pounds per square meters. inch of bolt cross-section.

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6. Tech A says that torque values are measured in foot- © Jones Review& Bartlett Questions Learning, LLC © Jones & Bartlett Learning, LLC pounds. Tech B says that torque values are measured NOT FOR SALE OR DISTRIBUTION NOT FOR 1.SALE Tech AOR says DISTRIBUTION that a hex bolt is usually used in con- in newton meters. Who is correct? junction with a flat nut. Tech B says that a split pin a. Tech A is usually used in conjunction with a castellated nut. b. Tech B Who is correct? c. Both A and B a. Tech A © Jones & Bartlett Learning, LLCd. Neither A nor B © Jones & Bartlett Learning, LLC b. Tech B NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION c. Both A and B 7. Tech A says that shaft strength refers to the amount d. Neither A nor B of force a bolt can take before it breaks. Tech B says that tensile strength refers to the amount of force a 2. Bolts are usually used for heavier jobs than screws. bolt can take before it breaks. Who is correct? © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC a. True a. Tech A b.NOT False FOR SALE OR DISTRIBUTION b. TechNOT B FOR SALE OR DISTRIBUTION 3. Tech A says that studs are commonly used to attach c. Both A and B a throttle body to the exhaust manifold. Tech B says d. Neither A nor B that studs are commonly used to attach a throttle 8. Keys are used to prevent the free rotation of gears or © Jones & Bartlettbody to theLearning, intake manifold. LLC Who is correct? © Jonespulleys & Bartlett on a shaft. Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION a. Tech A a. True b. Tech B b. False c. Both A and B d. Neither A nor B 9. Thread pitch is the measurement from the peak of © Jones & Bartlett Learning, LLCone thread to the next and© Jones indicates & theBartlett coarseness Learning, LLC 4. When you tighten a cylinder head bolt, the tighten- or fineness of the thread. ing sequence doesNOT not matter.FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION a. True a. True b. False b. False 10. The number stamped on the head of a bolt indicates 5. A torque angle gauge shows you the correct tighten- its size. ing© Jonesspecifications & Bartlett when Learning,you are tightening LLC a bolt. © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION a. TrueNOT FOR SALE OR DISTRIBUTION a. True b. False b. False

056754_CH04_p106-125.indd 124 3/12/14 9:24 PM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

056754_CH04_p106-125.indd 125 3/12/14 9:24 PM