When selecting a caster for your wire shelving unit, you must decide between threaded or stem styles. Each of these terms refers to the bolt that connects the caster to the shelving post. Threaded casters feature a 1/2" bolt with a specific threading (12 threads per inch) that screws directly into the bottom of our posts. Since there is no standard threading in the industry, these casters may not fit other brands of wire shelving, which is why we sell stem casters.
Stem casters are often called universal casters because they fit most 1" diameter shelving posts. The bolt on a stem caster is thick enough to act as a plug inside the bottom of posts, but are difficult to remove, making them a more permanent mobile solution. Some people prefer stem casters because they can be purchased without brakes, which aren't always necessary in mobile storage. Stem casters are compatible with our brand of shelving posts after you remove the threaded insert in the bottom of the post.