Frankly, I thought I'd get a better answer here.
It's really moot now, because I have a choice of GFN for only one size
sheave(I need 3 different sheaves) . I'll probably get it and try it because
the size might be better than the closest acetal sheave.

"Wayne.B" wrote in message
news
On Sat, 31 Jan 2009 09:35:42 -0500, "Garland Gray"
wrote:

I need to replace some old plastic sheaves, and I have the option of
sheaves
made of Delrin, acetal, or glass filled nylon. (I have learned that delrin
is acetal, but don't know if all acetal sheaves are delrin).
So what are the relative attributes of acetal and glass filled nylon
sheaves? I read somewhere that GFN might be more abrasive on the pin, but
I
assume that it is stronger. Ronstan sells both, but their website doesn't
solicit questions.

Why not give Ronstan or your local rigger a call and find out the pros
and cons of each?