When you need wheels or casters, either as replacements for your worn-out casters or for a piece of equipment that doesn’t already have wheels, it’s good to know the terminology. This is a quick primer. Casters have three basic parts: top plate, fork, and wheel. The top plate is exactly what it sounds like: a flat piece of metal, usually with four screw holes to attach it to the equipment. The fork is attached to the top plate and holds the wheel, with an axle going through the middle of the wheel and attaching to each side of the fork. The wheel is self explanatory. Some casters swivel, while others are rigid (can’t turn corners). When you call us looking for casters and wheels, we’ll use terms like “wheel diameter,” “top plate thickness,” and so on. If something doesn’t make sense, just ask. We’re here to help!