--RW90 is probably a reference to the "Rockwell hardness", which is
a standard scale. Applying it is probably done via some electronic
sputtering process; not sure if it needs to be done in a vacuum; that would
definitely bump up the price. For more on this you might try posting at
rec.crafts.metalworking (watch out for the jerks!) and possibly at
sci.engr.joining.welding, where the jerk ratio is tolerable.

--
"Steamboat Ed" Haas : Concave, convex, con
Hacking the Trailing Edge! : carne: all is Zen..
www.nmpproducts.com
---Decks a-wash in a sea of words---