Storage of Grinding Wheels
Grinding wheels must be handled with extreme care and tremendous importance should also be given to the method of storing them. A grinding wheel, if handled or stored badly, can cause serious problems when in operation. Given below are a few basic guidelines in handling and storing of grinding wheels:
On receipt of a wheel:
When you receive a grinding wheel, first check to see if the wheel shows any sign of damage, such as chipping, cracking or discolouration. If the wheel has any one of these problems, then it is damaged. Just reject the wheel.
Ring Test:
A ring test should always be conducted on receipt of a grinding wheel as well as before mounting it. This is mainly done to detect if there is any damage to the wheel. While conducting the ring test, small wheels should be held with the fore finger inside the bore while large wheels should be placed on a stand or support. The wheel should be tapped lightly with a non-metallic implement like a screwdriver handle in case of small wheels or a wooden mallet in the case of heavier wheels.
While conducting the ring test, tap the wheel on either side at 45°of its vertical axis and at 1" or 2" from its periphery. Rotate the wheel again to 45° and repeat the test till the entire circumference of the wheel is covered. A good wheel will give a clear ring while a cracked or damaged wheel will produce a dull sound. The wheel giving a dull sound should not be used.
A ring test should be held in a place where the 'ring' can easily be heard. It should be conducted only by a person qualified or skilled enough to interpret the result.
Rules for Grinding Wheel Storage:
► Wheels should not be exposed to freezing temperature conditions.
► Subjecting wheels to any extreme fluctuations in temperature should also be avoided. For instance, avoid any sudden variance in temperature that can cause condensation on the wheels when moving them from storage to an area of high temperature conditions.
► The outer surface of certain rubber, resinoid, shellac is magnesite wheels may be affected by oxidation if the wheels are stored for a long period. These wheels should not be stored beyond two years. Careful monitoring of stock is also required to ensure that earlier stock wheels are used first. However, vitrified grinding wheels can be stored for any period.
► Grinding wheels should be stored in racks or bins in such a way to prevent any damage to them. While removing a wheel, the adjacent wheels should not be disturbed.
The method for storing a grinding wheel, varies according to the wheel type:
► Flat cutting-off wheels should be placed without anything between them, on a flat surface of steel or a similar rigid material to prevent warpage. Thin wall, soft grade cylinder wheels (type 2), cup wheels (type 6), dish wheels (type 12) and saucer wheels(type 13) should be stored on flat sides with blotters or cushioning material between them.
► Thick rim, hard grade cylinder wheels, straight cup wheels and medium sized plain wheels may be stored on their periphery.
► Soft grade straight cup wheels and taper cup wheels (type 11) are best stored base to base, one the opposite way to the other, to prevent chipping of the edges and cracking of the walls.
► Large, plain and centreless wheels (Types 1,3 to 5,7,9,20 to 26,35 & 37) of considerable thickness must be stood on their sides, in racks and chocked so that they do not move or roll.
► Small wheels, up to 80 mm, mounted wheels and points, inserted nut cones (type 16 to 19) may be stored in appropriately sized boxes, bins, or drawers.
