I finally found a supplier for the rubber caster wheels on my delta contractor table saw. The old ones had chips and had worn quite badly. The supplier is in Pennsylvania of course but I used a digital caliper to measure the specifications. I sent for eight and I have installed them and they are an exact match for the old ones. I also have a stand for the radial arm saw but I put a band saw on it, uses the same retractable caster system.
-- bobdurnell, Santa Ana California.