I bought a set of four, two locking-swivel, two swivel only, from Woodcraft about 5 years ago and the outer red tread cracked and broke off. Woodcraft replaced them saying they had many complaints about the red tread cracking. The replacement also broke so I went with something solid. This is an assenbly/outfeed table and sees only light duty as far as weight goes. I though they should have lasted longer.