A grinding wheel is an expendable wheel that carries an abrasive compound on it's periphery.

The wheel is generally made from a matrix of coarse particles pressed and bonded together to form a solid, circular shape, various profiles and cross sections are available depending on the intended usage for the wheel. They may also be made from a solid steel or aluminium disc with particles bonded to the surface.

Materials used are generally silicon carbide and diamond.

The manufacture of these wheels is a precise and tightly controlled process, due not only to the inherent safety risks of a spinning disc, but also the composition and uniformity required to prevent that disc from exploding due to the high stresses produced on rotation.

Grinding wheels are self sharpening to a small degree, for optimal use they may be sharpened by the use of grinding dressers.

The wheel type (eg:- cup or plain wheel below) fit freely on their supporting arbors, the necessary clamping force to transfer the rotary motion being applied to the wheels side by identcally sized flanges (metal discs), the paper blotter shown in the images is intended to distribute this clamping force evenly across the wheels surface.

Safety

Safety is extremely important at all times, especially when grinding wheels are involved. They are a mainstay of the engineering and construction industry and the risks involved with them may tend to be taken for granted. Safety awareness and an understanding of the materials and processess involved is essential. Appropriate safety gear must be worn and all safety procedures must be followed. Err on the side of caution always.

Contact with a spinning grinding wheel will produce a cut, it may be thought that a burn would be produced (judging by the heat generated in the grinding process). Either way though, personal injury is the result. Wood should never be ground on a wheel, as it can clog the wheels pores and cause the wheel to burst, with fatal results.

Cup wheel

A cup wheel as pictured to the right, is predominately used in tool and cutter grinders where orientation of the wheel and slim profile are required. These wheels are used (and dressed) on the side face and have the advantage of producing a truely flat surface on the side of lathe tools

Straight wheel

To the left is an image of a straight wheel. These are by far the most common style of wheel and are commonly found on bench or pedestal grinders. They are used on the periphary only and therefore produce a slightly concave surface, this can be used to advantage on many tools such a chisels

Diamond wheel

At right is a Diamond wheel, these have industrial diamonds bonded to the periphery, they are used for grinding extremely hard materials such as carbide tips, gemstones or concrete. The saw pictured is a slitting saw and is designed for slicing hard materials, typically gemstones

Cut off wheels

Cut off or parting wheels are self sharpening, they are thin in width and often have radial fibres reinforcing them. Often used in the construction industry for cutting reinforcement steel (rebar), protruding bolts or anything that needs quick removal or trimming. Most handymen would recognise an angle grinder and the discs they use.