SECTION 7.3

Mismatching wheel and machine speeds can be dangerous. Recognizing this, wheel and machine manufacturers have agreed over the years on certain standard speeds to which both groups can design. Table 20 of the safety code defines these standard speeds. Although the typical wheel user will have little use of this complex table, he should be aware that it may affect the safety of his operations.

A sure and direct way for the wheel user to avoid mismatching is to routinely specify the actual speed of his machine on all orders for grinding wheels. In the absence of a speed call-out, the supplier will generally supply a standard-speed product. The max RPM marking of the wheel alerts the user not to use the wheel if the machine speed exceeds that standard speed. If such a potential mismatch occurs, return the wheel along with a notation of the actual machine speed.

To avoid speed mismatches, section 7 of the safety code recommends that speed checks be made periodically on all grinding machines. Specific times to do this are cited there by machine type.

A "special" speed is, by definition, any speed that exceeds the appropriate standard speed listed in Table 20 of the safety code. To maintain safety at these higher speeds, section 8 of the code places special requirements on the machine builder, the wheel manufacturer, and the wheel user. The chief responsibility of the user is to make certain that all guarding and other safety devices supplied with the machine are used and maintained in good working order, and that all safety precautions specified by the machine manufacturer are followed.

It is strongly recommended that users do not attempt to increase the wheel speed of any grinder beyond its original design value, nor alter its original guarding. Any intended modification of other safety-related equipment should first be discussed with and/or approved by the manufacturer.