Fastener Training Hex Head Cap Screw Hex Nuts Flat Washers

Home , Coupling nut, Flange nut, Jam nut, Nut (hardware), Square nut

Presented by Kevin Connolly Applications Engineer [email protected] Fastener Terms and Abbreviations

Below are three ways of describing the same fastener: 1. 1/4 – 20 UNC Class 2A x 1 Hex Head Cap Screw per ASME B18.2.1, Grade 5 per SAE J429, Zinc/Clear plated per ASTM B633 2. 1/4 - 20 x 1 Hex Cap Screw, Gr 5, Zn 3. 1/4 x 1 Hex Bolt, NC, 5, Z

Metric Fasteners: M10 x 50 Hex Bolt, Property Class 8.8, Y What it means: They want a 10mm diameter hex head cap screw with a coarse thread (1.5mm) that is made from a property class 8.8 steel and is plated zinc with yellow chromate.

The last three pages of this slide show contains a list of common abbreviations used when customers describe fasteners.

Bolts Screws (must be assembled with a nut) (can be assembled by head or with a nut) Dimensions for Hex and Heavy Hex Cap Screws specified by ASME/ANSI B18.2.1

Grade 8 Grade A490 Regual Hex Head Heavy Hex Cap Screw Cap Screw

Thread Length = 2 x Diameter + 1/4” (for lengths up to 6”)

Screw Sizes Coarse and Fine Threads Decimal Closest Decimal Inch Size Equivalent Metric Size Conversion Coarse (UNC) Fine (UNF) 1/4 - 20 .250" M6 x 1.0 .236" - 28 x 0.75

5/16 - 18 .3125" M8 x 1.25 .315" - 24 x 1.0 3/8 - 16 .375" M10 x 1.5 .394" - 24 x 1.25

7/16 - 14 .4375" - 20 1/2 - 13 .500" M12 x 1.75 .472" - 20 x 1.25

9/16 - 12 .5625" M14 x 2.0 .551" - 18 x 1.5

5/8 - 11 .625" M16 x 2.0 .630" - 18 x 1.5

M18 x 2.5 .709" x 1.5

3/4 - 10 .750" - 16

M20 x 2.5 .787" x 1.5 7/8 - 9 .875" M22 x 2.5 .866" - 14 x 1.5 1 – 8 UNC .945" 1.000" M24 x 3.0 - 12 UNF x 2.0 - 14 UNS 1 1/8 - 7 1.125" - 12

M30 x 3.5 1.181" x 2.0

1 1/4 - 7 1.250" - 12

M36 x 4.0 1.417 x 3.0 Ultimate Tensile Strength (UTS) Force required to cause failure in cap screw in axial direction.

Grade 1 60,000 psi minimum Grade 2 74,000 psi minimum Property Class 4.6 400 MPa min Grade 5 120,000 psi minimum Property Class 8.8 830 MPa min Grade 8 150,000 psi minimum Property Class 10.9 1040 MPa min Grade 9 180,000 psi minimum Property Class 12.9 1220 MPa min

If we had a bar that was heat treated to a Grade 8 strength level and the bar is one square inch in diameter, it would take 150,000 pounds to pull the bar apart. Inch Cap Screw Strength Designations

Inch Tensile Material Properties Strength Strength (min) Designations Bowmalloy 180,000 psi Alloy Steel Highest Strength (Grade 9) Excellent Wear and Abrasion Resistance SAE Grades Grade 8 150,000 psi Alloy Steel High Strength and Toughness Grade 5 120,000 psi to Carbon Steel Medium Strength 90,000 psi (standard)

Grade 2 74,000 psi Carbon Steel Low Strength Grade 1 60,000 psi ASTM Grades A490 150,000 psi Alloy Steel High Strength and Toughness A325 120,000 psi Carbon Steel Medium Strength 125,000 psi Alloy Steel Medium Strength B7 (A193) with Excellent Toughness A307 60,000 psi Carbon Steel Low Strength

Metric Cap Screw Strength Levels

Metric Tensile Material Properties Strength Strength (min) Designations

Property Class 12.9 1220 MPa Alloy Steel Highest Strength (177,000 psi) Excellent Wear and Abrasion Resistance Property Class 10.9 1040 MPa Alloy Steel High Strength and (150,800 psi) Toughness

Property Class 8.8 830 MPa Carbon Steel Medium Strength (120,350 psi) (standard)

Property Class 4.6 400 MPa Carbon Steel Low Strength (58,000 psi) Head Markings – Inch & Metric

Proprietary Grade

Grade 9

SAE Grades

Grade 1 & 2 Grade 5 Grade 8

ASTM Grades

A307 Grade A Grade B7 A325 A490

Metric Grades

Property Class 4.6 Property Class 8.8 Property Class 10.9 Property Class 12.9 Socket Products

Socket products do not come in different grades like hex head cap screws

Tensile Strength : Diameters 1/4 to 1/2” 180,000 psi min Diameters above 1/2” 170,000 psi min

Counterbore Screw Set screws used to hold shafts in place

12 Point Flange Screws are used to replace standard socket heads Hex Nuts

Finished Hex Finished Full Finished Thick Hex Hi Nut Coupling Nut Jam Nut Hex Nut Hex Nut

top is WAF chamfered

chamfered bottom has corners washer face Thickness Double Chamfered Nut Washer Faced Nut Heavy Hex Heavy Full Diameters 5/8 and smaller Diameters larger than 5/8 Jam Nut Hex Nut must be doulbe chamfered may be washer faced or doulbe chamfered

Hex Flange Nut Hex Nuts Heavy Hex Nuts Proof Load Proof Load Grade Hardness Grade Hardness Strength (psi) Strength (psi) UNC UNF 2 Rc 32 max (not defined) A Rb 68 / Rc 32 100,000 90,000 Dia Dia. UNC UNF UNC UNF

120,000 109,000 1/4 to 1 133,000 120,000 5 Rc 32 max 14/ to 1 5 Rc 32 max 1 1/8 to 1 1 1/8 to 1 1/2 105,000 94,000 1/2 116,000 105,000

UNC UNF

Dia C Rb 78 / Rc 38 144,000 (not defined)

1/4 to 5/8 Rc 24/32 Dia 3/4 to 1 Rc 26/34 UNC UNF 8 150,000 1/4 to 5/8 Rc 24/32 1 1/8 to 1 1/2 Rc 26/36 8 3/4 to 1 Rc 26/34 165,000 150,000 1 1/8 to 1 1/2 Rc 26/36 1/4 to 1 1/2 Rc 24/35 9 Rc 30/38 180,000 2H 175,000 above 1 1/2 Rb 95/Rc 35

Hex Nuts Heavy Hex Nuts Proof Load Proof Load Grade Hardness Grade Hardness Strength (psi) Strength (psi) UNC UNF 2 Rc 32 max (not defined) A Rb 68 / Rc 32 100,000 90,000 Dia

Dia. UNC UNF UNC UNF

120,000 109,000 1/4 to 1 133,000 120,000 5 Rc 32 max 14/ to 1 5 Rc 32 max 1 1/8 to 1 1 1/8 to 1 1/2 105,000 94,000 1/2 116,000 105,000

UNC UNF

Dia C Rb 78 / Rc 38 144,000 (not defined)

Metric Hex Nuts Property Hardness Proof Load (equivalent English Class Strength Units) 6 Rb 70/Rc 32 680 MPa 98,600 psi 8 M6 to M16 Rb 80/Rc 32 880 MPa 127,600 psi M16 > Rc23 / Rc 35 920 MPa 133,400 psi M4 to M10 1040 MPa 150,800 psi 10 Rc 26 / 36 M12 > 1060 MPa 153,700 psi

Slotted Nuts

Slotted Hex Finished Slotted Thick Slotted Castle Nut Heavy Full Jam Nut Hex Nut Hex Nut Hex Nut

Legs of cotter pin bent open to hold nut in place

Nut installed at point where hole is visible

Grade 5 Hex Slotted Nuts 1/4 thru 1 UNC Over 1” UNC 1/4 thru 1 UNF Over 1 UNF 96,000 psi min 87,000 psi min 84,000 psi min 75,000 psi min

Grade 8 Hex Slotted Nuts 1/4 thru 1 1/2 120,000 psi min Hex Nut Grade Markings

SAE markings

* *

Old SAE Marking

ASTM marking

* * Lock Nuts

All Metal Lock Nuts Nylon Insert Lock Nuts

Flange Lock Nuts

Proof Load Max Grade of Cap Screw IFI Grade For Sizes Strength to be used with Grade A #4 to 1 1/2 (UNC & UNF) 90,000 Grade 2 #4 to 1” (UNC & UNF) 120,000 Grade B Grade 5 1 1/8 to 1 1/2” (UNC & UNF) 105,000 Grade C #4 to 1 1/2 (UNC & UNF) 150,000 Grade 8

Grade F 1/4 thru 3/4 120,000 Grade 5 Grade G 1/4 thru 5/8 150,000 Grade 8

Proof Load Max Grade of Cap Screw to SAE Grade For Sizes Strength be used with Grade 2 1/4 to 1 1/2 (not defined) Grade 2 1/4 to 1” (UNC) 120,000 1/4 to 1” (UNF) 109,000 Grade 5 Grade 5 1 1/8 to 1 1/2 (UNC) 105,000 1 1/8 to 1 1/2 (UNF) 94,000 Grade 8 1/4 to 1 1/2 150,000 Grade 8 Flat Washers

Fender Washer (Widest Style)

USS Washer SAE Washer (Wide Sereis) (Narrow Series)

F436 Washer Thick Washer

Flat Washers are not graded. There is no grade 8 or grade 5 washer

Three Types • Carbon Steel (aka, low carbon steel or steel) For Grade 1, 2 or 5 • Case hardened steel For Grade 5 • Through Hardened For Grade 8 Types of Applications

Steel

1 1/2 x Dia

Blind (or Tapped) Nut and Bolt Hole Assembly Assembly

Gasket

Copper

Aluminum

Gasketed Joint Clamping Soft Assembly Metals Platings & Coatings

Zinc Yellow

Hot Dip Galvanized

Zinc Plated (Zinc/Clear) Furnace Black (Plain) (black oxide from heat treatment) Plain (non-heat treated)

Corrosion Protection Coating Salt Spray Hours Hot Dip Galvanized 240 hrs Zinc Yellow 96 hrs Zinc Plated (Zn/Clear) 72 hrs Furnace Black 4 hrs Plain 0 hrs Torque Calculations for Fasteners Standard industry practice for calculating torque for a fastener assembly is to use the formula Torque = Clamp Load x Diameter x Friction Factor / 12 (T=PxDxK/12)

The desired clamp load is usually based on 75% of the Yield Strength (or Proof Load Strength) of the threaded fastener used in the assembly (the nut used should be compatible with the strength of the threaded component). The Friction Factor is based on the surface finish of the two components being assembled. If both components have a plain steel finish then the Friction Factor (K) is assumed to be .20. The use of lubricants on the threads can reduce the Friction Factor to .12 and the addition of platings that do not slide across each other well can increase the Friction Factor to .22 (for zinc plating). The table listed below shows the recommended clamp loads for Grade 2, 5 and 8 assemblies (per SAE J429 and J995).

Recommended Clamp Load Recommended Torque (based on 75% of Cap Screws Proof Load) (for plain finish assemblies)

Gr 2 Gr 5 Gr 8 Torque Torque Torque Grade 2 Grade 5 Grade 8 Diameter TPI Area Stress Clamp Ft-Lbs Ft-Lbs Ft-Lbs Clamp Load Clamp Load Load (lbs) (lbs) (lbs) Dry Lubed Dry Lubed Dry Lubed (K=.20) (K=.15) (K=.20) (K=.15) (K=.20) (K=.15) 20 0.0318 1312 2027 2862 5 4 8 6 12 9 1/4 28 0.0364 1502 2321 3276 6 5 10 7 14 10 18 0.0524 2162 3341 4716 11 8 17 13 25 18 5/16 24 0.058 2393 3698 5220 12 9 19 14 27 20 16 0.0775 3197 4941 6975 20 15 31 23 44 33 3/8 24 0.0878 3622 5597 7902 23 17 35 26 49 37 14 0.1063 4385 6777 9567 32 24 49 37 70 52 7/16 20 0.1187 4896 7567 10683 36 27 55 41 78 58 13 0.1419 5853 9046 12771 49 37 75 57 106 80 1/2 20 0.1599 6596 10194 14391 55 41 85 64 120 90 12 0.182 7508 11603 16380 70 53 109 82 154 115 9/16 18 0.203 8374 12941 18270 79 59 121 91 171 128 11 0.226 9323 14408 20340 97 73 150 113 212 159 5/8 18 0.256 10560 16320 23040 110 83 170 128 240 180 10 0.334 13778 21293 30060 172 129 266 200 376 282 3/4 16 0.373 15386 23779 33570 192 144 297 223 420 315 9 0.462 11435 29453 41580 167 125 430 322 606 455 7/8 14 0.509 12598 32449 45810 184 138 473 355 668 501 8 0.606 14999 38633 54540 250 187 644 483 909 682 1 14 0.68 16805 43286 61110 280 210 721 541 1019 764 7 0.763 18884 42347 68670 354 266 794 595 1288 966 1 1/8 12 0.856 21186 47508 77040 397 298 891 668 1445 1083 7 0.969 23983 53780 87210 500 375 1120 840 1817 1363 1 1/4 12 1.073 26557 59552 96570 553 415 1241 930 2012 1509

All material included in this table is for reference purposes only and its use by anyone is entirely voluntary. Reliance on its contents by anyone for any purpose is at the sole risk of that person. Earnest is not responsible for any loss, claim or damage arising therefrom. In developing these tables, Earnest has made a determined effort to present the contents accurately. • Common Abbreviations used with Fasteners • 18-8 Stainless Steel with 18% Chrome and 8% Nickel • 2, 5 or 8 Strength grade of screw or nut • 2A (3A) Class of Thread Fit for inch screws • 2B (3B) Class of Thread fit for inch nuts • 2H Nut strength level designation (ASTM A194 Grade 2H Heavy Hex Nut) • 6g Class of thread fit for metric screws • 6H Class of thread fit for metric nuts • A325 Heavy Hex Structural Bolt (ASTM A325), similar to Grade 5 • A490 Heavy Hex Structural Bolt ASTM A490), similar to Grade 8 • A574 Strength grade for Socket head cap screws (ASTM A574) • AISI American Iron and Steel Institute, specifies chemical composition of steels • ANSI American National Standards Institute • AS Alloy Steel • ASME American Society of Mechanical Engineers • ASTM American Society for Testing and Materials • B When followed by a number (ex B-90) hardness measured on the Rockwell B Scale • or an abbreviation for Boron • Bake (Bake-Out) Heat Treat process used in plating to prevent Hydrogen Embrittlement • Bevel Style of washer (square with a taper) used with I beams • Belleville Style of lock washer, also called conical spring washer • BHCS Button Head Cap Screw • BHN Hardness measured with a Brinell Hardness Tester • BS British Standard • C When followed by a number (ex C-35) hardness measured on the Rockwell C Scale • or an abbreviation for Carbon • CH Case hardened (type of heat treatment) • C/R Cross Recess Drive (typically Phillips style) or Chamfer/Radius • Cad Cadmium Plating • CAD Computer Aided Design/Drafting • Cad/Wax Cadmium Plating with a topcoat of Wax • COO Country of Origin • CRES Corrosion resistant steel (usually refer to 18-8 or 316 stainless steel) • CS (cs) Carbon Steel or Countersunk • DAC (Dac 320) Dacromet Coating (Registered Trademark of Coatings International) • D/C Nut Double Chamfered Nut (distinguish from washer faced) • D/E Double Ended Stud • DIN German Standards Organization • Deltaseal Magnigard coating (registered trademark of Magni Engineered Coatings) • Dorrltech Magnigard coating (registered trademark of Magni Engineered Coatings) • Driseal Pipe Thread (registered trademark of Parker Hannifin) • ET External Thread • FB Flange Bolt • F436 Hardened flat washer with dimensions per ASTM F436 • FHCS Flat Head Cap Screw • FIM Full Indicator Measurement • Flng Hex Flange Bolt or Nut • FW Flat Washer • galv Galvanized, typically refers to Hot Dip Galvanized • Gr Grade, refers to strength level of screw or nut (ex: Grade 2, Grade 5 or Grade 8) • Hardened A product that has been heat treated • HB Hex bolt or Hardness reading measured on the Brinell Scale • H.T Heat Treated • HCS Hex Cap Screw or High Carbon Steel • H.D.G. Hot Dip Galvanized • Hex Bolt Can refer to either a “bolt” or a “cap screw” • HHCS Hex Head Cap Screw (also an abbreviation for Heavy Hex Cap Screw) • HRB Hardness measured on the Rockwell B scale • HRC Hardness measured on the Rockwell C scale • HWH Hex Washer Head • ID Identification (usually refers to manufacturer logo) • IFI Industrial Fastener Institute • IH Indented Head • in. Inch • ISO International Standards Organization • ISIR Initial Sample Inspection Report • IT Internal Thread • J429 SAE standard that specifies strength levels of screws • J995 SAE standard that specifies strength levels of nuts • k Short hand for the number 1,000 • Keps Nut with a permanently attached washer • Kips 1,000 pounds • ksi Thousand of pounds per square inch • lb (lbs) Pounds • Lb Body Length on screws • LCS Low Carbon Steel • Lg Grip Length (distance from head to full threads) on screws • LH Left Hand Thread • L/W Lock Washer • M Metric or short hand for the number 1,000 • Magnigard Magni Coating (Registered Trademark of Magni Engineered Coatings) • Mfg Manufacturer • mm Millimeter • MS Machine screw • MTR Material Test Report • #3 (or #7) Refers to head design of a plow bolt • NC Unified National Coarse Thread • NE (NU, NTE, NTU) Designations that define the thickness of Nylon Insert Lock Nuts • NF Unified National Fine Thread • Nom Nominal (reference dimension) • NPT National Tapered Pipe Thread • p Thread Pitch • P/B Plow Bolt • Ph Dr Phillips Drive (cross recess) • Pl Plain finish • P/N Part Number • Phos (P & O) Phosphate and Oil Coating (typically Zinc Phosphate and Oil) • Pozi Drive Special cross recess (registered trademark of Camcar Textron) • PPAP Production Part Approval Process • psi Pounds per square inch • PZ Pozi-Drive style of cross recess • R Radius • Rb (RB or HRB) Hardness measured on the Rockwell “B” scale • Rc (RC or HRC) Hardness measured on the Rockwell “C” scale • RT Rolled Threads • SAE Society of Automotive Engineers, • when used with washers it means “small OD” • when used with screw or nuts means fine thread • Screw Can refer to any type of externally threaded fastener but typically a sheet metal screw • Sems Screw with a permanently attached washer • Serrated Locking serrations on bearing face of screw or nut • SHCS Socket Head Cap Screw • Sl Slotted Drive • SMS Sheet Metal Screw • Sq Square, can refer to square head bolt or square nut • SS or S/S Stainless Steel • St Steel • Taptite Special triangular thread forming screw (registered trademark of Reminc) • T.H. Through Hardened (type of heat treatment) • TIR Total Indicator Reading • T/S Tapping Screw • Torx 6 Lobe Drive (Torx Drive, registered trademark of Camcar Textron) • TPI Threads per Inch • TT (TR) Taptite thread (registered trademark of Reminc), also called Tri-Roundular • TTH Threaded to Head • Type 1 (23, 25) Special thread forming or cutting tapping screws • Type AB (F, T) Special thread forming or cutting tapping screws • UNC Unified National Coarse Thread • UNRC Unified National Coarse Thread with Radius Root (standard rolled thread form) • UNF Unified National Fine Thread • UNRF Unified National Fine Thread with Radius Root (standard rolled thread form) • UNJ Unified National Thread with Large Radius Root (special fatigue resistant thread) • UNR Unified National Thread with radius root • USS United States Standard • when used with washers it is for large OD • when used with screws or nuts it means coarse thread • UTS Ultimate Tensile Strength • WAC Width Across Corners • WAF Width Across Flats • W/F Washer Faced (can refer to a Nut or Cap Screw) • Whitworth British Thread Standard (not the same as UN threads) • Y Yellow Chromate • YS Yield Strength • Zn Zinc, usually referencing zinc plating (assumed to be zinc with clear chromate) • Zn/C (ZC) Zinc Plating with Clear Chromate topcoat • Zn Phos Zinc Phosphate and Oil (same as Phos and Oil) • Zn/Wax Zinc Plating with a topcoat of wax • Zn/Y (ZY) Zinc Plating with Yellow Chromate topcoat