Portable Power Tools

Chapter 296-807, WAC

Effective Date: 08/01/03

Helpful Tools

Helpful Tool: Ring Test

A ring test should be performed before mounting an abrasive wheel. This test is simple and can help determine if the wheel is cracked.


The wheel has to be dry and free of sawdust when applying the ring test, otherwise the sound may be deadened.

The ring test doesn’t work with certain wheels because of their shape or size.

Examples include:

  • Wheels 4 inches diameter and smaller
  • Plugs and Cones
  • Mounted Wheels
  • Segments
  • Plate-Mounted Wheels
  • Inserted Nut and Projecting Stud Disc Wheels

How to do the test:

(1) Suspend the wheel by putting a small pin or your finger through the arbor hole in the wheel. Heavier wheels may be allowed to rest in a vertical position on a clean hard floor (See Illustration 1).

(2) Tap the flat side of the wheel with a light non-metallic implement, such as the handle of a screw driver, at a point

  • 45 degrees from the vertical center line on each side of the wheel (See Illustration 2)
  • 1 – 2 inches from the edge of the wheel. Large, thick wheels may be struck on the periphery rather than the side of the wheel.

(3) Rotate the wheel 45 degrees and repeat the test until the entire wheel has been checked.

How to use the results:

The ring test depends on the fact that a crack in the wheel will normally change the sound emitted when the wheel is lightly tapped. An undamaged wheel will give a clear tone. If cracked, there will be a dead sound and not a clear ring.

Comparison of the sound with other wheels of the same lot and specification will allow rejection of any wheel with a suspiciously different ring.

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