Working Safely with Cut-Off Machines

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Working safely with cut-off machines

© ANDREAS STIHL AG & Co. KG, 2009 Printed on chlorine-free paper Original Instruction Manual 0457-186-0121. M3.L09.FST. Printing inks contain vegetable oils, paper can be recycled. 0000000551_001_GB anPrs18 16 12 2 13 9 Parts Main Maintenance and Care 12 wheels cutting Diamond Composite resin cutting wheels Cutting wheels Sample applications Techniques Safety Precautions and Working Working safely with cut-off machines { Contents STIHL servicingdealer. this brochure, please contact your If you still have questions after reading cut-off wheel must be observed. information sheets enclosed with the respective cut-off machineandthe Thus the Instruction Manual for the the specific machines. chapters intheInstructionManuals for This brochure contains references to have different controls. example. Other cut-off machines may 420 cut-off machine as an shows the TS machine" the of parts "Main chapter The STIHL cut-off machines. described in the Instruction Manuals for precautions and working techniques This brochure contains the safety English 1 English

Safety Precautions and When not using the machine, it must be The machine may only be used for laid down in such a way that it does not cutting. It is not suitable for cutting wood Working Techniques endanger anyone. Ensure that the or wooden objects. machine cannot be used without Special safety precau- Asbestos dust is extremely toxic - the authorization. tions must be taken when machine must therefore never be used working with a cut-off The user is responsible for accidents or to cut asbestos! machine, due to the very risks involving third parties or their Other uses are not permitted and may high rotational speed of property. lead to accidents or damage to the the cutting wheel. The machine should only be provided or machine. loaned to people familiar with this model It is important that you Never modify the machine in any way, and its operation. The Instruction carefully read the entire as this could be extremely dangerous. Manual should always be handed over Instruction Manual before STIHL excludes all liability for personal with the machine. using the machine for the injury and damage to property caused first time and keep it in a Use of machines that emit noise may be while using unauthorized attachments. safe place for future ref- restricted in terms of time by national Only use cutting wheels and erence. Non-observance and/or on-site, local regulations. of the following safety attachments which have been approved precautions may cause The machine may only be operated by by STIHL for this machine or which are serious or even fatal people who are fit, in good physical technically equivalent. Contact a dealer injury. health and in good mental condition. if in doubt. Only use high-quality cutting wheels and attachments. Otherwise If you have any condition that might be Observe the national safety regulations there may be a risk of accidents or aggravated by strenuous work, check issued, for example, by the employers' damage to the machine. liability insurance association, social with your doctor before operating a security institutions, occupational safety machine. STIHL recommends the use of genuine STIHL cutting wheels and attachments. and health authorities or other If you have a pacemaker: The ignition These have been optimized for the organizations. system of your machine produces an product and the user's requirements. If you have never used a power tool electromagnetic field of very low before: have your STIHL dealer or other intensity. An effect on individual Do not use high-pressure cleaners to specialist show you how to operate the pacemaker types cannot be excluded clean the machine. The hard water jet machine – or attend one of the special entirely. STIHL recommends that you can damage parts of the machine. consult your doctor and the training courses. Do not spray the machine with water. manufacturer of your pacemaker in Minors should never be allowed to use order to avoid health hazards. the machine – except for young trainees over the age of 16 when working under Anyone who has consumed alcohol, supervision. medicines affecting their ability to react or drugs must not operate the machine. Keep children, animals and bystanders well away from the machine. Postpone the work if the weather is bad (snow, ice, wind) – higher risk of accidents!

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Never use circular saw Do not wear clothing that could become Transporting the machine blades, carbide, rescue trapped in moving parts of the machine or wood cutting attach- – no scarves, no neckties, no jewelry. Always stop the engine. ments or saws of any Long hair must be tied up and covered. kind – these may cause Carry the machine only by the top Wear safety boots with fatal injuries! Instead of handle – cutting wheel towards the rear steel toe caps and non- uniformly removing parti- – with the hot muffler facing away from slip soles. cles as when cutting with the body. a cutting wheel, the teeth Avoid touching hot parts of the machine, of a circular saw blade especially the surface of the muffler – may snag in the material. Wear a hard hat wher- risk of burns! This causes the machine ever there is any risk of to react in a highly falling objects. Wear a Never transport the machine with the aggressive manner with face shield and always cutting wheel fitted - it may break! uncontrolled and wear safety glasses – In vehicles: Properly secure your extremely dangerous danger due to flying machine to prevent turnover, damage kickback. objects. and fuel spillage. A face mask alone is not sufficient to Clothing and equipment protect the eyes. Refueling Dust (e. g., crystalline material from the Wear proper protective clothing and object being cut), fumes and smoke may Gasoline is an equipment. be produced while cutting - health extremely flammable Clothing must be sturdy hazard! fuel – keep clear of and snug-fitting, but allow Always wear a dust mask if dust is naked flames and fire – complete freedom of generated. do not spill any fuel – no movement. Wear snug fit- smoking. ting clothing with cut- If fumes or smoke are anticipated (e. g., Switch off the engine before refueling. retardant pads – an over- when cutting composite materials), wear all, not a loose-fitting respiratory protection. Never refuel the machine while the jacket. Wear "personal" hearing protection – engine is still hot – the fuel may spill over – risk of fire! When cutting steel, always wear clothing e. g., ear defenders. made of barely flammable material (e.g., Wear heavy-duty, non- Open the fuel filler cap carefully so that leather or cotton with flame-retardant slip gloves – preferably any excess pressure is relieved finish) – no manmade fibers – risk of made of leather. gradually and fuel does not splash out. fire due to flying sparks! The machine may only be refueled in a Ensure that there are no flammable well ventilated place. Clean the machine deposits (chips, fuel, oil, etc.) on the STIHL can supply a comprehensive immediately if fuel is spilled. Change clothing. range of protective clothing and your clothes immediately if they are equipment. contaminated with fuel.

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Dust may collect on the engine unit, Cut-off machine, spindle bearing The permissible speed of particularly around the carburetor. If the the cutting wheel must be dust is soaked with gasoline, it may equal to or greater than A faultless spindle bearing ensures the catch fire. For this reason, ensure that the maximum spindle radial and axial runout of the diamond the dust is always removed. speed of the cut-off cutting wheel – have this checked by a machine! Refer to the Check for fuel leakage dealer if necessary. chapter "Specifications". while refueling and during operation. Never start the Cutting wheels Before fitting a used cutting wheel, engine if fuel has been check that it is not cracked, chipped, or spilled or is leaking – uneven, and does not display any signs Fatal burns may result! Selecting cutting wheels of core fatigue or overheating (discoloration); check also that there are Various cut-off machines may be Cutting wheels must be approved for no damaged or missing segments and equipped with various filler caps: freehand cutting. Do not use any other that the spindle bore is not damaged. cutting wheels or attachments - risk of Bayonet filler cap accidents! Never use a chipped, cracked or warped cutting wheel. Cutting wheels are suitable for varying materials: Observe the cutting wheel Substandard and/or unapproved codes. diamond cutting wheels can shimmy during cutting. This shimmying can STIHL generally recommends wet cause such diamond cutting wheels to cutting. be abruptly braked or become stuck in Observe the outer diame- the cut – Danger of kickback! ter of the cutting wheel. Kickback can result in fatal cuts! Diamond cutting wheels that shimmy Never use a tool to open or close the constantly or even only intermittently bayonet filler cap. This could damage must be replaced immediately. the cap and cause fuel to leak out. Never straighten diamond cutting The diameter of the spin- wheels. Secure the bayonet filler cap tightly after dle hole of the cutting refueling. wheel and the shaft of the Never use a cutting wheel that has been cut-off machine must dropped – a damaged cutting wheel may Threaded filler cap match. break – risk of accident! Close the threaded filler Check spindle hole for damage. Do not Observe the use-by date where resin cap as tightly as possible use cutting wheels with a damaged cutting wheels are concerned. after refueling. spindle hole – Risk of accident! Mounting cutting wheels Check the cut-off machine spindle, do This helps reduce the risk of unit not use cut-off machines with damaged vibrations causing an incorrectly spindles – risk of accident! tightened filler cap to loosen or come off and spill quantities of fuel. Note the arrows indicating the direction of rotation on diamond cutting wheels.

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Position front thrust washer – tighten – Never attempt to modify the controls Hand-held cutting tensioning nut – turn cutting wheel by or safety devices hand, in the process making a visual – Keep the handles dry and clean – inspection for radial and axial runout. free from oil and dirt – for safe Storing cutting wheels control of the cut-off machine Store cutting wheels in a dry, frost-free The machine should only be used if it is place, on a flat surface, at constant in good working order – risk of temperatures – danger of breakage accident!

and shattering! 337BA047 KN Starting the engine Always protect cutting wheels against Always hold the machine firmly with sudden impact with the floor or objects. both hands: Right hand on the rear Move at least 3 meters away from the handle – even if you are left-handed. To Before starting place at which the machine was refueled ensure reliable control, wrap your and never start the machine in enclosed thumbs tightly around the handlebar and spaces. handle. Check that the cut-off machine is in good condition - refer to the corresponding The machine may only be used on level chapters in the Instruction Manual: ground. Ensure a firm and secure footing and hold the machine firmly. The – The cutting wheel must be suitable cutting wheel must not touch any objects for the material to be cut. It must be or the ground and must not be in the cut. in good condition and fitted correctly (direction of rotation, securely The cutting wheel may begin to rotate as seated). soon as the machine is started. The machine is operated by only one – Check that the deflector is secure - 180BA022 KN consult a STIHL servicing dealer if it person. There should not be any other When a cut-off machine with rotating is loose person within the working area, not even when starting the machine. cutting wheel is moved in the direction of – The throttle trigger and throttle the arrow, a force is produced which Do not drop-start the engine – start as trigger interlock must move easily – causes the machine to tip sideways. throttle trigger must return described in the Instruction Manual. The object that is to be cut must be automatically to the idle position The cutting wheel continues to run for positioned firmly; always guide the when released some time after the throttle trigger has machine to the workpiece – never vice been released – Risk of injury due to – Slide control / master control / stop versa. switch must move easily to coasting effect! STOP or 0 Cut-off machine cart Holding and guiding the machine – Check that the spark plug boot is STIHL cut-off machines can be mounted secure. A loose boot can lead to on a STIHL cut-off machine cart. flying sparks which may ignite the The cut-off machine may only be used escaping fuel/air mixture – risk of for freehand cutting or when mounted on fire! a STIHL cut-off machine cart.

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Deflector Never work on a ladder or on any other Ensure proper ventilation when working unsteady support. Do not work above in trenches, hollows or other confined shoulder height and never operate the locations – risk of serious or fatal The adjusting range of the deflector is machine with one hand - risk of injury from breathing toxic fumes! determined by a stop pin. Never attempt accidents! to push the deflector over the stop pin. If you feel sick, if you have a headache, Ensure you always have a firm and safe vision problems (e.g., your field of vision footing. gets smaller), hearing problems, dizziness or inability to concentrate, stop Do not work alone – keep within calling work immediately. Such symptoms may distance of others in case help is be caused by an excessively high needed. concentration of exhaust emissions – Never allow anyone in the working area risk of accident! and keep well away from other people to No smoking when working with or near protect them from noise and flying

002BA223 KN the machine - risk of fire! objects. If the machine is subjected to unusually Set the deflector correctly for the cutting More care and attention than usual are high loads for which it was not designed wheel: so that particles of material are required when wearing ear protection, (e.g., heavy impact or a fall), always guided away from the user and machine. as sounds warning you of impending check that it is in good condition before danger (shouts, beeps, etc.) cannot be Note the direction in which the cut continuing work - refer also to the heard properly. particles are ejected. section "Before starting". Check the fuel If you get tired, take a break in good system for leaks and make sure the During work time. safety devices are working properly. Work calmly and methodically – only Never use the machine if it is not in good In the event of impending danger or in with good lighting and visibility. Take condition. Consult a servicing dealer if in an emergency, switch off the engine care not to endanger other people! doubt. immediately by moving the slide control Do not work in the starting throttle Your power tool produces / master control / stop switch to position, as the engine speed cannot be toxic exhaust fumes as STOP or 0. controlled in this position. soon as the engine is Check for correct idling, so that the running. These gases Never touch a rotating cutting wheel with cutting wheel is no longer driven when may be colorless and your hand or any other part of the body. the throttle trigger is released and odorless and may contain Examine the workplace. Avoid all comes to a complete halt. unburnt hydrocarbons danger due to damaged piping or and benzene. Never run Check and/or correct the idle setting electrical wiring. regularly. Have the machine repaired by the engine indoors or in a STIHL servicing dealer if the cutting poorly ventilated areas, The machine must not be used near wheel continues to turn nevertheless. even if your model is inflammable substances or gases. equipped with a catalytic Never use the machine to cut inside Ensure that the working area is clear – converter. watch out for obstacles, holes and pits. pipes, metal troughs or other containers unless you are absolutely sure that they Beware of slipping on ice, water, snow do not contain any volatile or or uneven ground! inflammable substances.

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Never leave the machine unattended with the engine running. Switch off the engine before leaving the machine (e. g., for a break). Before putting the cut-off machine down on the ground: – Switch off engine 002BA146 KN – Wait until the cutting wheel has 002BA189 KN come to a standstill or brake the Kickback occurs when the cut-off – Always be aware that the object to cutting wheel until it comes to a machine is suddenly thrown up and back be cut may move and other factors standstill by carefully touching a in an uncontrolled arc towards the may cause the cut to close and jam hard surface (e. g., concrete slab) operator. the cutting wheel. Inspect cutting wheel fre- Kickback occurs if, for example, the – The object to be cut must be quently – replace cutting wheel secured and supported so that the immediately if there is cut remains open during and after – becomes jammed – above all in the evidence of cracking, cutting upper quarter warping or other damage – Work with water and wet cutting (e. g., overheating) – risk – is severely braked through frictional when using diamond cutting wheels of accident due to contact with a solid object breakage! – Depending on version, composite Reduce the risk of kickback resin cutting wheels are suitable for In the event of changes in cutting – Work cautiously and methodically dry cutting or wet cutting only. behavior (e. g., increased vibration, Always use wet cutting with reduced cutting performance), stop work – Hold the cut-off machine firmly with composite resin cutting wheels that and eliminate the causes of the both hands and maintain a secure are suitable only for wet cutting changes. grip Pulling away Reactive forces

The most frequently occurring reactive forces are kickback and pull-in.

Dangers of kickback Kickback can result in fatal cuts. 002BA190 KN

– Do not use the upper quarter of the 002BA188 KN cutting wheel for cutting. The cutting The machine pulls forward, away from wheel must be introduced into the the user, when the cutting wheel cut with extreme care, without touches the object to be cut from above. twisting and without pushing

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Working with the cut-off machine the machine while in the cut – do not cutting wheels of this type become wet, drop the machine into the cut – danger their cutting performance is reduced and of breakage! they become dull. If composite resin The cutting wheel must cutting wheels of this type become wet Diamond cutting wheels: If cutting be guided straight in the while working (e. g., due to puddles or performance begins to deteriorate, cut, without wedging. water in pipes), do not increase the check the sharpness of the diamond Never exert lateral pres- cutting pressure, but continue working cutting wheel, resharpen as needed. To sure on the cutting wheel. with the same pressure – risk of do this, briefly cut through abrasive breakage! Wet composite resin cutting Do not use the cutting material, e. g., sandstone, aerated wheels must be used up immediately. wheel for lateral grinding concrete or asphalt. or scrubbing. At the end of the cut, the cut-off machine Cut-off machine cart is no longer supported by the cutting Clear a path for the cart. If the cart is wheel in the cut. The machine's weight pushed over objects, the cutting wheel must be borne by the user, otherwise may become wedged in the cut and you may lose control of the machine! shatter! When cutting steel: glow- ing metal particles may Vibrations cause fires! Prolonged use of the power tool may result in vibration-induced circulation 002BA059 KN Keep water and sludge away from problems in the hands ("white finger Do not stand in line with the cutting electric cables - risk of electric shocks! disease"). wheel. To obtain a clean cut: the cutting wheel No general recommendation can be Do not lean too far forwards and never should be pulled into the workpiece if given for the length of usage because it bend over the cutting wheel, especially possible or moved back and forth in depends on several factors. cutting direction. It must never be when the deflector has been pulled The period of usage is prolonged by: back. pushed. – Hand protection (wearing warm Work with water and wet cutting when Don’t cut above shoulder height. gloves) using diamond cutting wheels – e. g., The cut-off machine may only be used use STIHL water attachment. – Work breaks for cutting. It must not be used as a lever or shovel. Depending on version, composite resin The period of usage is shortened by: cutting wheels are suitable for dry – Any personal tendency to suffer Do not press down on the cut-off cutting or wet cutting only. machine. from poor circulation (symptoms: Work with water and wet cutting when frequently cold fingers, tingling Always decide the cutting direction using composite resin cutting wheels sensation) before positioning the cutting wheel. that are suitable only for wet cutting – – Low outside temperatures After that, do not change the cutting e. g., use STIHL water attachment. direction. Avoid knocks and bumps with – Amount of gripping force (holding Use dry cutting when using composite the power tool tightly restricts resin cutting wheels that are suitable circulation) only for dry cutting. If composite resin

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Users who use the machine periodically Do not service or store the machine near Sample applications or for long periods or users who a naked flame – risk of fire due to the repeatedly experience corresponding fuel. symptoms (e.g., tingling sensation in Check fuel cap regularly for tightness. fingers), should undergo a medical Water must always be used for wet examination. Use only spark plugs that are in perfect cutting when working with diamond condition and have been approved by cutting wheels Maintenance and repairs STIHL – see Specifications. Inspect ignition lead (insulation in good The machine must be serviced regularly. condition, secure connection). Do not attempt any maintenance or Check that the muffler is in perfect repair work not described in the working condition. Instruction Manual. All other work should be carried out by a servicing dealer. Do not use the machine if the muffler is damaged or missing - risk of fire! – STIHL recommends that maintenance Hearing damage! and repair work be carried out only by authorized STIHL dealers. STIHL Never touch a hot muffler – risk of burns! dealers receive regular training and are Extend service life and increase supplied with technical information. Check the rubber buffers underneath cutting speed Use only high-quality replacement parts, the machine - the housing must not rub against the ground - risk of damage! Always ensure a supply of water to the in order to avoid the risk of accidents or cutting wheel. damage to the machine. Contact a The condition of the antivibration dealer if in doubt. elements influences vibration behavior – Bind dust STIHL recommends the use of genuine inspect antivibration elements periodically. The cutting wheel must be supplied with STIHL spare parts. Such parts have at least 0.6 l/min of water. been optimized for the machine and the user's requirements. Water attachment Before starting any maintenance or – Water attachment on the machine repair work and before cleaning the for all types of water supplies machine, always stop the engine and disconnect the spark plug boot – risk – Pressurized water tank 10 l for of injury if the engine starts up binding dust inadvertently! – Exception: adjustment – water tank usable on the cut-off of carburetor and idle speed. machine cart for binding dust To reduce the risk of fire due to ignition outside the cylinder, move the slide control / stop switch to STOP or 0 before turning the engine over on the starter with the spark plug boot removed or the spark plug unscrewed.

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Use composite resin cutting wheels – Water attachment on the machine Cut in several passes with or without water – depending on for all types of water supplies version – Pressurized water tank 10 l for binding dust Depending on version, composite resin – water tank usable on the cut-off cutting wheels are suitable for dry machine cart for binding dust cutting or wet cutting only. Observe with diamond and Composite resin cutting wheels suitable only for dry cutting composite resin cutting wheels During dry cutting, wear a suitable dust mask. Object to be cut N Mark cutting line (A) If fumes or smoke are anticipated (e. g., – Must be fully supported when cutting composite materials), wear – Must be secured so it cannot roll or respiratory protection. slip off Composite resin cutting wheels – Must be prevented from vibrating suitable only for wet cutting Severed parts Use cutting wheel only with water. With openings, recesses, etc., the sequence of the cuts is important. Always make the last cut so that the N Work along the cutting line. When cutting wheel does not become jammed making corrections, do not tilt the and so that the operator is not cutting wheel, but always set the To bind dust, the cutting wheel must be endangered by the severed or cutting wheel against the workpiece supplied with at least 1 liter of water per separated part. anew – the cutting depth for each minute. To avoid a reduction in cutting operation should not exceed 5 to performance, the cutting wheel must be If necessary, leave small ridges that hold the part that is to be separated in 6 cm. Cut thicker material in multiple supplied with not more than 4 liters of operations water per minute. position. Break these ridges later. After using the cutting wheel, the wheel Before finally separating the part, should be allowed to continue spinning determine: at operating speed for – how heavy the part is approx. 3 to 6 seconds without water in order to spin off the water remaining on – how it can move after separation it. – whether it is under tension When breaking out the part, do not endanger assistants. N sever large wall thicknesses with even back and forth movements

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Cutting plates Shaping pipe

N Secure the plate on a non-slip surface

N Make curves in multiple operations – make certain that the cutting wheel does not tilt N Mark a cutting line Cutting round and hollow bodies Manual cutting along this line N Grind a guide groove (A) along the requires particular caution and line marked precision.

N Secure pipes, round bodies, etc. N Make the cut (B) deeper with even against rolling away N Grind a guide groove along the back and forth motions marked cutting line – do this by N when determining the cutting line, starting at the apex and cut outward N Leave a "hinge" (C) avoid reinforcement, especially in on both sides N First sever the plate at the cut ends the direction of the severing cut N Cut into pipes, round bodies, etc. in so that no material breaks away N Grind a guide groove along the line the area at the ends of the cutting marked N Break plate line, so that the material does not N Make cuts deeper with even back break away and forth motions – feed with full N Make cuts deeper with even back cutting depth along the guide and forth motions – start at the apex groove – for small corrections of and cut outwards on both sides – direction, do not tilt the cutting feed with full cutting depth along the wheel, but always position it anew guide groove – for small corrections instead – if necessary, leave small of direction, do not tilt the cutting ridges that hold the part that is to be wheel, but always position it anew separated in position. Break these instead – if necessary, leave small ridges later

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ridges that hold the part that is to be Cutting wheels Composite resin cutting separated in position. Break these ridges later wheels Cutting wheels are exposed to extremely high loads especially during freehand cutting. The cutting wheels, which have been developed by STIHL in cooperation with renowned manufacturers of abrasive wheels, are of high quality and tailored precisely to the respective intended use as well as the engine performance of the cut-off machine. The proper selection and use of They are of consistently outstanding composite resin cutting wheels ensures quality. economical use and avoids accelerated wear. The code on the Transport and storage – label – of the packaging (table with – Do not expose cutting wheels to recommendations for use) is an aid direct sunshine or other thermal to selection stresses during transport and STIHL composite resin cutting wheels storage are suitable, depending on the version, – Avoid jolting and impacts for cutting the following materials: – Stack cutting wheels flat on a level – Asphalt surface in the original packaging in – Concrete a dry place where the temperature is as constant as possible – Stone – Do not store cutting wheels in the – ductile cast iron pipes vicinity of aggressive fluids – Steel – Store cutting wheels in a frost-free STIHL composite resin cutting wheels place are not suitable for cutting railway tracks.

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Diamond cutting wheels Product Codes

An excessively high radial run-out deviation (A) overloads individual diamond segments, which overheat in The product code is a combination of the process. This can lead to stress The proper selection and use of one to four letters and numbers: diamond cutting wheels ensures cracks in the parent wheel or to economical use and avoids accelerated – the letters denote the main field of annealing of individual segments. wear. The code on the application of the cutting wheel Deviations in axial run-out (B) result in – label Letter Main field of higher thermal loading and wider cuts. application – of the packaging (table with recommendations for use) is an aid A Asphalt to selection B Concrete STIHL diamond cutting wheels are BA Concrete, asphalt suitable, depending on the version, for S Stone (hard stone) cutting the following materials: SB Hard stone, concrete – Asphalt – the numbers denote the – Concrete performance class of the STIHL diamond cutting wheel – Stone (hard stone) – abrasive concrete Axial and radial run-out – Fresh concrete A faultless spindle bearing of the cut-off – Clay brick machine is necessary for a long service – Clay pipe life and efficient functioning of the diamond cutting wheel. STIHL diamond cutting wheels are not suitable for cutting metal. Using the cutting wheel on a cut-off machine with a faulty spindle bearing can lead to deviations in radial and axial run-out.

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Troubleshooting

Cutting wheel Error Cause Remedy ragged edges or cut surfaces, crooked Deviation in radial or axial run-out Contact a servicing dealer1) cut heavy wear on the sides of the segments Cutting wheel gyrates use a new cutting wheel ragged edges, crooked cut, no cutting Cutting wheel is dull; built-up edges with cut- Sharpen cutting wheels for stone by performance, generation of sparks ting wheels for stone briefly cutting through abrasive materials; replace cutting wheel for asphalt with a new one poor cutting performance, high segment Cutting wheel is turning in the wrong Mount cutting wheel so that it turns in the wear direction right direction Breakdowns or tears in the parent wheel Overloading use a new cutting wheel and segment Undercut Cutting in the wrong material use new cutting wheel; observe separating layers of various materials 1) STIHL recommends STIHL servicing dealers

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Undercut – when cutting extremely hard materials, e. g., granite – with incorrect handling, e. g., excessive feed effort – if excessively large cross-sections are cut without pendulum cutting (movement back and forth in the cutting plane) Built-up edges increase vibration, reduce cutting performance, and cause Do not cut into the base course formation of sparks. (frequently chipped stones and gravel) when cutting roadway pavement – At the first signs of built-up edges, cutting in chipped stones and gravel is immediately "sharpen" the diamond revealed by light-colored dust – cutting wheel – to do this, briefly cut excessive undercut may occur as a through abrasive material such as result – Danger of shattering! sandstone, aerated concrete or asphalt. Addition of water prevents the formation Built-up edges, sharpen of built-up edges.

Built-up edges take the form of a light If work continues with dull segments, gray deposit on the tops of the diamond these may soften due to the high heat segments. This deposit on the segments generated – the parent wheel is clogs the diamonds and blunts the annealed and its strength is segments. compromised – this can lead to stresses Built-up edges can form: that are clearly recognizable by gyrations of the cutting wheel. Do not continue to use the cutting wheel – Risk of accident!

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Maintenance and Care

The following maintenance intervals apply in normal operating conditions. The specified intervals must be shortened accordingly when working for longer than normal or under difficult cutting conditions (extensive dust, etc.). before starting work at the end of work and/or daily Whenever tank is refilled Weekly Monthly Yearly If faulty If damaged As required Visual inspection (condition, leaks) XX Complete machine Clean X

Operating elements Check operation XX

test, check X Fuel pick-up body in fuel tank Replace XXX

Fuel tank Clean X Clean / retension XX Ribbed V-belt Replace XX

Air filter (all filter components) Replace Only if there is a noticeable loss of engine power

Cooling air intake slits Clean X Have them cleaned by a specialist Cylinder fins X dealer 1)

test, check X Spark arresting screen2) in muffler Clean or replace X test, check xx Water attachment Have them maintained by a specialist x dealer1)

Check idle adjustment – abrasive XX Carburetor wheel must not rotate Readjust idle speed X

Adjust electrode gap X Spark plug Replace after 100 hours’ operation

All accessible screws, nuts and bolts (not Retighten XX adjusting screws)

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Antivibration elements Have them replaced by a specialist X dealer1) test, check XX Abrasive wheel Replace XX

Supports/rubber buffers (underneath the test, check X machine) Replace XX

Safety information sticker Replace X

1) STIHL recommends STIHL servicing dealers 2) present only in some countries

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Main Parts

1 Rear handle 2 Throttle trigger interlock 10 3 Throttle trigger 4 Slide control 4 5 Starter grip 2 6 Carburetor adjusting screws 7 Filler cap 1 5 3 9 8 Water attachment 9 Tensioning nut 6 10 Adjusting lever 11 11 Cutting wheel 7 12 Front thrust washer 13 Deflector 14 Muffler 15 Spark arresting screen (present 8 only in some countries) 16 Handlebar 17 Decompression valve 18 Cap for spark plug boot 16 19 Choke lever 13 18 20 Fuel pump 17 21 Filter cover # Serial number 19 14 20 15

# 370BA046 KN

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