On 31/07/2011 03:07, Christopher Tidy wrote:
Christopher Tidy wrote:
Quick question. Does glass-filled nylon have good bearing properties?
I would have expected its bearing properties to be poor, because wear
would essentially cause particles of sand to break off, but I have
been told otherwise. The product in consideration is a ground nylon
piston in a reamed brass cylinder. A little lubrication, but not a
lot. Anyone know?

Incidentally, I should add, this is a reverse-engineering situation. I'm
trying to figure out what material a defunct company used. The plastic
layer is transparent with a yellowish tint.

Chris

How long is a piece of string? A few more details about the application
would help, dimensions / load / pressure / sliding speed / how many
cycles or how far do you need it to slide? Do you want the cheapest
solution, or is it an expensive bit of kit that you don't mind spending
money on?

Transparent doesn't sound like glass filled nylon, more like acrylic,
polycarbonate, perhaps epoxy?

Glass filled nylon is cheap, readily available, easy to machine. There
are also nylons which contain some oil to make them more self-lubricating.

PTFE is pretty good, though not so strong. Fabric reinforced phenolic is
strong, but less happy at combination of high load and sliding speed.
Polyimide (e.g. Vespel) is the Rolls Royce material for many
applications, but not cheap.