SECTION 7.4

All grinding wheels can be broken or damaged and should be handled as fragile items. The as-manufactured strength of wheels depends upon their bond type, grit size, grade, shape, and size. However, careless storage, handling, transport, mounting, or usage can degrade this original strength by breaking or weakening the bonding material that holds the wheel together.

Inspection. Wheels should be visually inspected for chips, cracks, or other indications of rough handling. This should be done when they are first removed from their shipping container, or as soon as damage to the container is noticed. Immediately discard or return to the manufacturer any wheel showing such damage. It is important that these wheels be segregated so they cannot possibly be used.

Handling, In-Plant Transport. All wheels are impact-sensitive and should be protected from sudden shocks. They should not be moved or supported by metal devices, e.g. lift truck forks or hoist hooks, unless the metal contact areas are covered by resilient material. Any wheel that is dropped should be considered damaged. Do not roll wheels on the shop floor--cover the path with clean, staple-free cardboard. Do not lay wheels directly on any metal, brick, or similar hard, rigid surface.

Storage. Store wheels on resilient material and only in places that are dry and free from extremes of temperature and humidity. Water-soaking can gradually weaken resinoid wheels; telephone the manufacturer for advice if this happens. Both resinoid and vitrified wheels should be considered unsafe if they are wetted and then subjected to freezing temperatures. A ring test should not be relied upon to detect the widely distributed damage due to freezing a damp wheel