Your shop cart or equipment trolley still has the same casters it came with — and they lock up on debris, skip over uneven concrete, or the wheel wobbles under load until the entire assembly starts pulling sideways. Cheap casters drag the job down before you're halfway through. 2-1/2-inch rigid plate-mount caster in black. The rigid design rolls straight under heavy loads without the swiveling drift that makes plate carts pull to one side. Plate-mount attachment gives you four-bolt stability that rivet-on or stem-mount casters can't match — the kind of connection that holds when you're pushing a loaded welding cart across rebar-covered floor. The 2-1/2-inch wheel diameter handles most shop and warehouse surfaces without snagging on small debris, and the black finish keeps the look clean on Stocked at Crofton Lumber and Akron Lumber.