"Capt. JG" wrote in message
.. .
I remember long ago, when I re-rigged by Cal 20 it had sheaves
specifically for wire. I switched to spectra and switched the sheaves to
Delrin, which I took to be the standard. I recall there are also aluminim
sheaves that accept both line and wire. Delrins are injection molded, so
I'd think that there might be some inconsistencies in them from time to
time. I believe the GFN sheaves are also injection molded but stronger.
Looks like there are also Delrin GFNs... :-)

http://www.jacoproducts.com/materials/thermoplastic.htm

--
"j" ganz @@
www.sailnow.com

Both my CT-41 (first boat) and my Rawson 30 (current boat) had wire crab
winches for the main and jib halyards when I bought them. The first thing I
did was to replace those wrist-breakers and get rid of all those fish hooks.
Now with the ultra-low-stretch super-strong lines being available in small
diameter, I have to wonder whether wire tails couldn't be replaced with the
new technology. No fish hooks, anyway. But I still loath crab winches.