CASTER WHEELS 101

What Are Casters?

Casters are wheels that allow for mobility on various types of furniture and machinery. The basic anatomy of a caster is a single wheel housed within a metal frame. You will often find caster wheels under racks, bar carts, shopping carts, swivel office chairs, recliners, workbenches, and industrial machines.

What to Consider When Choosing a Caster

LOAD RATING – How much weight can each caster wheel hold? To calculate your required load rating, read on.
FLOORING SURFACE – Is your floor rough or uneven? You can compensate for this in a couple ways: First, a durable tire material, such as polyurethane or rubber, can absorb shock. Second, larger wheels roll easily over rough/uneven surfaces.
BRAKE OPTIONS – If your floor is sloped, you will need a locking brake to prevent your furniture from rolling downhill.
SWIVEL vs. NON-SWIVEL – Do you need a caster that is omni-directional so it can rotate 360 degrees? Be sure to know the “swivel radius” (the radius of the space measured from the vertical centerline of the swivel section that is required to allow a caster to swivel 360 degrees).
MOUNTING TYPE – There are two options for attaching a caster to your furniture/equipment: top plate or stem. A top plate is a flat, square-shaped metal bracket with holes for drilling. In contrast, a stem is a cylindrical-shaped rod that is placed inside an object’s mounting slot of the same shape and size. The rod can be plain or threaded. To learn how to measure the stem diameter, read on.

How to Determine a Caster’s Load Rating

for a four-wheel cart:

Add the weight of your cart and the weight of the load being carried. Take that total and divide it by 4. This gives you the minimum rated load capacity each caster wheel should have.

for a three-wheel cart:

Add the weight of your cart and the weight of the load being carried. Take that total and divide it by 3. This gives you the minimum rated load capacity each caster wheel should have.