Traditional threaded stem casters work by screwing into place. Ensure you're purchasing the right sized caster for your piece of equipment—because after all, you might find there's a big difference in size when it comes to casters for your mop bucket than say, your oven. Stock up on several threaded stem casters so you're always ready for an unexpected break. No one wants to be the person responsible for taking out that heavy trash can with a broken dolly!