Without a doubt, a top plate is the most common means of mounting a caster. From small to large, light to heavy, top plates provide the most secure and convenient method of mounting. A top plate doesn’t need an explanation to understand how it works, a plate with holes that one puts bolts through.
Measuring the right things
With that being said, there is some nuance to getting the right bolt hole pattern. This is critical in replacement applications, the wrong pattern will mean having to return and exchange the caster or having to drill new holes on existing equipment. A typical bolt hole pattern reads as follows:
- 2-5/8″ x 3-5/8″ slotted to 3″ x 3″
This means that the holes on the outside most part of the plate are 2-5/8″ x 3-5/8″ then slotted to the inner part at 3″ x 3″. The image to the right illustrates this well. Some top plates do not come with slotted holes, others have holes slotted in other directions. Generally speaking, a caster series, with the exception of furniture casters, is defined by its top plate size.