• Inspect and conduct "a ring test" before mounting a wheel.
• Check the flanges for distortion or abrasion. When flanges are distorted or warped contact area is reduced.
• Flanges must not be reversed.
• Use blotters to cushion flange pressure.
• Do not use flat washers or other filler materials in place of flanges.
• The fixed and loose flanges should have the same diameter and have undercut relief. The minimum flange size is 1/3 of the wheel diameter.

• For cup wheels, use a flat unrelieved flange with a threaded hole mounting. This flange prevents strain on the bond that anchors the bushing to the wheel cup.

For cone and plug wheels, the common cause of breakage occurs when that the spindle threads are either too short or too long for the tapped hole in the wheel.
How should you mount depressed centre wheels?

• Replace any worn or bent reusable adapters. A damaged adapter will not mount properly.
• Do not reuse "throw away" adapters.
• Ensure that the grinder spindle shoulder runs true. The adapter must tighten against this shoulder. Use spacers provided with adapters if the spindle is too long.
• The wheel will wobble if the shoulder is not square with the spindle, or if the adapter does not tighten against the shoulder. This can result in wheel breakage and injuries to the operator or a nearby worker.