8Cutting metalsIMPORTANT!Always wear approved respiratory protection!Materials that can release toxic substances may be cut only after notifying theproper authorities and under their supervision or that of a person appointedby them.CAUTION:The rapid rotation of the cutting disc heats metal and melts it at the point ofcontact. Swing the guard as far down as possible behind the cut (19) in orderto direct the stream of sparks forward, away from the operator (fire hazard).- Determine the direction of cutting, mark the cut and apply the disc to the materialat moderate speed, to cut a guide groove before going to top speed and applyingmore pressure to the Power Cutter.- Keep the disc straight and vertical. Do not tip it, as this can break it.- The best way to get a good, clean cut is to pull or move the Power Cutter backand forth. Do not simply press the disc into the material.- Thick round stock is best cut in stages (20).- Thin tubing and pipes can be cut with a simple downward cut.- Cut large-diameter pipes as for round stock. To prevent tipping and for bettercontrol, do not let the disc sink too deeply into the material. Instead, always cutshallow around the whole piece.- Worn discs have a smaller diameter than new discs, so that at the same enginespeed they have a lower effective circumferential speed and therefore do not cutas well.- Cut I-beams and L-bars in steps; see Figure 21.- Cut bands and plates like pipes: along the wide side with a long cut.- When cutting material under stress (supported material or material in structures),always make a notch in the thrust (pressure) side, and then cut from the tensionside, so that the disc does not lock in. Secure cutoff material from falling!CAUTION:If there is a chance that the material is under stress, be prepared for it to kickback. Make sure you can get out of the way if you have to!Be particularly careful in scrap-metal yards, junkyards, at accident sites,and with haphazard piles of material. Precariously balanced pieces or piecesunder stress can act in unpredictable ways, and may slide, jump out, or burst.Secure cutoff material from falling! Always exercise extreme caution and useonly equipment that is in perfect working order.Observe the accident-prevention rules and regulations of your employer and/or insurance organization.Cutting masonry and concreteIMPORTANT!Always wear approved respiratory protection!Asbestos and other materials that can release toxic substances may be cutonly after notifying the proper authorities and under their supervision or thatof a person appointed by them. When cutting prestressed and reinforcedconcrete piles, follow the instructions and standards of the responsibleauthorities or the builder of the structural member. Reinforcement rods mustbe cut in the prescribed sequence and in accordance with applicable safetyregulations.NOTE:Mortar, stone, and concrete develop large quantities of dust during cutting. Toincrease the lifetime of the cutting disc (by cooling), to improve visibility, and toavoid excessive dust creation, we strongly recommend wet cutting instead of drycutting.192021