Cobalt info..

[dannyvi]

I just picked up some cobalt blanks and found out they are magnetic. Did I get ripped off? I thought cobalt was nonmagnetic. Guy insists it's genuine cobalt for blades. Any advise??

 

[mete]

Iron, nickel,cobalt,gadolinium are ferromagnetic. Genuine cobalt for blades ?? Is it cobalt or steel with cobalt or a cobalt alloy like Talonite ?

 

[dannyvi]

I really have no idea what kind it is. The seller said it has to be annealed then made into a blade. He does say it is cobalt.It is very heavy and very hard.My file hardly dents it!

 

[mlovett]

If a file can scratch it at all, in its hardned state, there's somthing not quite right.

 

[DaveH]

I had a cobalt knife from Boye, it was non magnetic.

 

[Stacy E. Apelt - Bladesmith]

I have talked to Dan about this material,and I suspect the blank is HSS with cobalt,often refereed to as "cobalt steel".It is used for lathe tools.Often marked P-8-X,it contains 8% cobalt.It could make a small blade,but would perhaps tend to chip easily? Lateral stress would have to be avoided.
Dan is going to send me the blanks and I will try to see what they are and make him a blade from it.
For those who are wondering,elemental cobalt is magnetic.Dendritic cobalt (David Boye's stuff) is not.Neither is Talonite,if I remember right.I know of no one using pure cobalt for knife blades.Cobalt alloys for knife work are not generally annealed or hardened.It is tough and will take a fair edge.Its big feature is non corrosiveness.
Dendritic cobalt,stellite,talonite are all alloys of predominantly cobalt with chromium,molybdinum, tungsten, manganese, iron, carbon,and other elements added.Cobalt is about 50-55% of the mix.Here is a bunch of info:
http://www.geocities.com/mdpoff/talonite.html