3 Grinding WheelsA grinding wheel is an expendable wheel that is composed of an abrasive compound used for various grinding and abrasive machining operations.
4 Grinding Wheels Many different styles available Choose correct type & grit of wheelReplace once when wheel reaches ½ of its original diameter.
5 Ring TestGood – RingBad – ThudALWAYS TEST WHEELS BEFORE INSTALATION
6 Wheel Identification Size: Grit : How aggressive the wheel will grind 10” x 1.5” x 1.25”Wheel Diameter x thickness x arbor sizeGrit : How aggressive the wheel will grindHigher Grit = Smoother WheelRPM : How fast the wheel can spin safelyUse wheels that meet or exceed the grinder RPM rating!Color:Grey & Brown – workhorse grits, mild steelsPink & White – harder steels that require cool grinding surfaceRuby Red – Tool steels and sharpening
11 Dressing a Grinding Wheel Adjust tool rest to proper gap for dressingTurn on grinderHook dressing tool on tool restPut light pressure on wheel while moving back and forthContinue until wheel is smoothReadjust tool rest to 1/16”LINK
12 Don’t grind soft metals! Aluminum, copper, brass, etc.The metal is too softThe heats up and melts into the grainIt will need to be dressed
13 Safety Rules:Adjust tool rest to 1/16” MAX from wheel
14 NEVER GRIND ON THE SIDE! The sides are not trued during manufacturing They are not evenThe sides are not trued during manufacturingNot designed to handle heavy loads.May shatter leading to a very nasty result.
15 Safety Rules PPE – Glasses, shield, dust mask, ears NEVER wear gloves!Hold the piece with a locking pliers if it gets hot.Stand to the side during startupInspect wheelRe-Dress uneven or loaded wheelsWear a maskKeep rest 1/16” from wheel
16 Safety Rules: Hold work by hand or with a clamp or vice grip Do not adjust or repair while grinder is runningDO NOT FORCE IT!Keep your work piece on the tool rest at ALL times
17 Portable Disc Grinder Angle Grinder Hand Grinder
18 Types of Discs 1. Grinding wheel Weld preparation Removing slag/unwanted welds2. Fiber Cut-off WheelMetal cuttingUse at a 90 degree angle only3. Flap Disc / Sanding DiscMetal finishing4. Cup brushUsed for removal of paintWeld cleanupHold with EXTRA force!
19 Standard DiscsUsed for grinding, de-scaling, polishing, blending, and finishing.Semi-flexible backingFits curved & rough surfacesLeaves a smooth & swirl-free finish.
20 Raised Hub / Type 27 Hub is raised in the center 1/8” thick ¼” thick Light GrindingCutting offNotching¼” thickHeavy duty grinding only
21 Saucer Shaped / Type 28 Identified by saucer shape. Easier to use than raised-hub discsDesigned to be held at shallow angles
22 Changing the Discs UNPLUG IT!!!!!!!!!!!! Engage the spindle lock Use the correct size wrenchWear gloves and remove wheelSnug new wheel with arbor wrench!
23 Can be a workout Using the portable disc grinder is hard work Rest frequently to avoid fatigue
24 Fighting Fatigue – Handle Attachment Reduces stress on hands and armsNecessary for deep cutsMakes it easier for disc change-over
25 Fighting Fatigue- Speed Lock Locks the grinder into full speed(Cruise-Control)Convenient for heavy grindingSeveral stylesAll are located on the power switch
26 Safety Rules PPE: Eye protection, long sleeve leather gloves face shield is recommendedUse correct wheel for the applicationCheck condition of wheel before each useReplace once wheel is half goneDo not remove the wheel guardsSecure your work pieceShoot your sparks in a safe directionLET THE GRINDER DO THE WORKNever set it down on while the disc is spinning
27 Pneumatic Grinders Use compressed air instead of electricity Better for extended grinding applicationsNeed a good air-compressor to keep upSame attachments available as electric