can't find chair leg inserts

hi, first timer.
i have chairs with 1" metal tubular legs and i need to find the inserts or gliders that fit on the bottom. i want the one that push inside the leg tube. i need 18 of them. can anyone point me in the right direction. i have tried home depot, lowes and ace hardware. i think i found some on-line but the minimum order is $25.00.
i would prefer metal but at this point i will take the plastic/vinyltype.

i live in mass. near the city of brockton

thanks for any help