Found this gem (see FDA letter below) in a pile of paper materials to be shredded. It is important to note that reducing metal contamination to food is an important goal.
Nobody wants steel shavings in their cornflakes!
"After reviewing the information provided, we find that you cobalt alloy is expected to be resistant to corrosion and abrasion, and its components will not migrate significantly to food. Further, in the past, we have stated that we do not object to the use of Cobalt alloys in food processing equipment. We find no reason to alter this opinion, based on the information you have provided. Therefore, we have no objection to the use of your cobalt alloy in food-contact processing equipment."
-Dept of Health and Human Services, Food and Drug Administration
Download letter here
More information on 6B properties and specifications.
6B is Rockwell C 33-43 hardness by specification AMS 5894 UNS R30016.
The composition also covers Alloy 6BH, which is a harder version of 6B.
6BH has a minimum hardness of Rc 40. This is very similar to 6K, but with higher ductility (less brittle).
One of the applications that 6BH has been used in food service was as a scraper for making cornflakes. The material would peel the slurry from the drum.
6B was originally invented by Elwood Haynes, and was used as tooling for machining. It was one of the first applications of Tungsten Carbides being used for machining. Machining tools have become harder (and more brittle) since then.
HPAlloys has this material melted in the USA, and we process it from ingot to slabs, billet, bars and narrow plate at Tipton, Indiana. Tipton is only a short drive from Kokomo, where Elwood Haynes began his historic journey as an inventor and metallurgist.