Mach 122: Abrasive Machining GRINDER SAFETY Compiled by: Ronald C.Schwartz 09/09/09

SAFETY FIRST To reduce the safety hazards from wheel explosions, wheel guards are used on nearly every type of grinding machine. Safety guard on a surface grinder. (DoALL Company) Compiled by: Ronald C.Schwartz 09/09/09

SAFETY FIRST A vitrified bond grinding wheel can be “ring tested” for possible cracks. Hold the wheel on your finger or on a small pin. Tap lightly with a wooden mallet or screwdriver handle. A good wheel will give off a clear ringing sound, whereas a cracked wheel will sound dull. Ring tests should be made a total of four times, indexing the wheel in 90-degree increments. Fig. L-35 Making a ring test on a small wheel. Compiled by: Ronald C.Schwartz 09/09/09

Grinding Wheel Safety Rules SAFETY FIRST Grinding Wheel Safety Rules Rule 1 Handle and store grinding wheels carefully Rule 2 Never use wheels that have been dropped. Rule 3 Inspect all wheels for cracks or chips before mounting, and ring test them. Rule 4 Do not alter a wheel to fit the grinding machine; do no force it on the machine spindle. Fig. L-36 Store extra wheels in a cabinet. The main requirement is to keep the wheels separate or protected, and off the floor (Asnuntuck Community College). Compiled by: Ronald C.Schwartz 09/09/09

Grinding Wheel Safety Rules SAFETY FIRST Grinding Wheel Safety Rules Rule 5 Make sure operating speed never exceeds maximum allowable operating speed of the wheel. Rule 6 Ensure that mounting flanges have equal and correct diameters, and bearing surfaces must be clean for using mounting flanges. Rule 7 Use mounting blotters unless the wheel is designed for some other mounting method. Compiled by: Ronald C.Schwartz 09/09/09

Grinding Wheel Safety Rules SAFETY FIRST Grinding Wheel Safety Rules Rule 8 Do not over tighten the mounting nut. Rule 9 If the machine is a pedestal or bench grinder, adjust the work rest, not to exceed 1/16”. clearance. Rule 10 Do not grind on the side of a straight wheel. There are certain detailed exceptions to this rule. In applications such as shoulder and form grinding, some amount of side grinding takes place. Compiled by: Ronald C.Schwartz 09/09/09

Grinding Wheel Safety Rules SAFETY FIRST Grinding Wheel Safety Rules Rule 11 Use a safety guard that covers at least half of the grinding wheel, and do not start the machine until the guard is in place. Rule 12 Allow the grinding wheel to run at least one minute before using it to grind. Rule 13 Do not stand directly in line with the rotating grinding wheel, and always wear approved safety glasses or other eye protection. Rule 14 Use the correct wheel for the material you are grinding. Compiled by: Ronald C.Schwartz 09/09/09

Grinding Wheel Safety Rules SAFETY FIRST Grinding Wheel Safety Rules Rule 15 Be sure there is no possibility of bump collision between the grinding wheel and the workpiece before starting the grinding machine. Especially critical in cylindrical and surface grinding. Rule 16 Turn off grinding fluid before stopping the wheel to avoid creating an out-of-balance condition. If the fluid is applied through the wheel, let the wheel run for at least a minute after the grinding fluid is stopped. Compiled by: Ronald C.Schwartz 09/09/09

QUESTIONS? Compiled by: Ronald C.Schwartz 09/09/09