Originally Posted by
sced
Oops...me bad. The ones I'm using came from a clamp-on I bought in 1977, so mine are steel
true
the parts list drawing shows "661" - the plastic rings - for the brazed-mount version; the clamp-on version doesn't have those, the function is held by the rings attached at "660" and yes,all of those i've seen were metal, i think bronze or brass (?) may be wrong here!