Grinders perform a wide variety of operations — all at high speeds. As with every power tool, operators must give grinders their undivided attention. Remind students to always check the wheel for tightness before each use, and never use cracked or damaged grinding wheels. (At the high speeds that grinders turn, rotational forces can cause faulty wheels to fly apart, throwing sharp fragments in many directions at high velocity.)

Here again, guards are critical in preparation for an unexpected event. They will help to protect the operator from potentially lethal flying fragments, should the grinder wheel break up in use.

Refer to...

Safety is Specific, page 15. (Bench
and Portable Disc Grinders)

Safety is Specific, page 17. (Rotary
Die Grinder)

... for references to the safe use of grinders.
Lesson Suggestion... Help Someone Else Learn

Objective: Get students to thoroughly absorb use and care
procedures for a tool that they must teach to someone else.

Materials/Requirements: A cooperative volunteer student
or two.

What To Do: After students have gained a level of familiarity
with the grinder or other tool, invite another teacher or adult who
has no experience with the tool to visit your classroom. Have
your students take turns instructing the newcomer in various
aspects of using and caring for the tool - set up, use,
maintenance, clean up. Make sure your students stress the
importance of the use of the guards.

    Are the students able to convey what they know? Do they
themselves thoroughly understand what they are trying to teach
the visitor? Encourage them to press each other for more
information and better explanations. Students should prepare for
this class with a group discussion in which they arrive at a basic
outline for teaching the tool.