Grinding Wheel Types

This old grinding wheel uses a slow speed for sharpening tools.

A grinder is one of the most useful power tools for the home workshop. Grinders can be used for sharpening tools, shaping parts for construction projects and improving the surface finish of items. In addition to the standard bench grinder, various types of hand-held grinders are available. All of these grinders should be fitted with the proper grinding wheel for the job at hand. Does this Spark an idea?

Spindle Mount

Grinding wheels that are intended for bench grinders are usually spindle mount, meaning they have a hole of a specified diameter to fit tightly over a spindle. A washer and either a nut or bolt then secures the wheel in place. Grinding wheels of this design are generally rated for slow to medium speed, or under 3500 rpm maximum.

Flange Mount

Hand-held angle grinders typically use a flange mount. A flange mount grinding wheel also has a hole, but it is much larger than the spindle diameter. A flange fits over the spindle, followed by the grinding wheel. Next, a second flange threads over the spindle, clamping the wheel between the two flanges. A shoulder on one of the flanges fits the mounting hole in the wheel. This method of clamping the wheel withstands side forces that are common when using an angle grinder. These grinders operate at high speeds of 6000 to 15000 rpm.

Integral Shaft

Grinding wheels that are intended for small air- or electric-powered tools commonly have an integral shaft to fit a chuck or collet in the machine. Although this type of mount does not resist side loading as well as a flange mount, it allows a greater variety of tool attachments such as drill bits and carbide burrs. Grinding wheels for these tools must be capable of withstanding extremely high speeds of up to 30,000 rpm.

References

• Global Spec: Grinding Wheels Specifications
• Georgia Grinding Wheel: Grinding Wheel and Abrasives Basics