Caster is one of the most widely used products in the civilized world. Their applications ranging from shopping wheels to conveyors, from moving goods to moving people, from the high flying aircrafts to the bottom-rolling furniture dollies. The modem life can not function with these little casters.
Caster is also existing in many forms: from hi-tech stainless steel to old fashion rubber, from with steel bearing to not bearing at all, from as small as half an inch to as big as 16 inch or even more.
Therefore, there is no one simple and easy formula to be followed in selecting the right casters to be used. There are many factors that must be considered to make the proper selection under the circumstances. It is generally recommended to make the selection based on the eventual required application of the caster:
The several application factors to be considered are:
Load Requirement:The heavier the load, the larger the wheel required for the caster. The weight of the load also influences the mobility of the wheel. Roller or ball bearings are recommended for loads over 400 pounds. Weight capacities are generally different for casters in different size and made of different material. Roller bearings carry heavier loads. Ball bearings roll easier but carry lesser loads. When possible, use the largest ball bearing wheel for best results.
Conditions of contact surface:The size of the wheel must be large enough to pass over anticipated cracks, tracks, bumps, and other obstructions in the contacting surface. One must also take into account if the contact surface needs to be protected or if the contact surface will harm the caster.
For example: for contact surface such as linoleum, tile, carpet, etc., polyurethane or Performa rubber wheels are probably preferred to avoid tear.
Reverse is also true. If there is acids, oils, chemicals or other conditions that could harm the wheels, then one must select the wheel material accordingly. For example, if there is acid on the contact surface, then polyurethane, polyolefin or phenolic wheels are probably better.
Operating Temperature:Temperature outside of room temperatures is generally no problem for most casters. However, extremely low and high temperature can and will be a problem. Some casters are just not meant to be used in extremely cold and hot temperatures.
Rule of the Thump: Check application conditions, then select caster.