Question about 5160 from Jantz

[pastormarty]

I just got my first order of bar stock to try my hand at knife making. I know the O-1 and 1095 are annealed, but the 5160 looks like it has a dark gray coating on it. Is this because it is annealed but not precision ground? Do I need to do anything more than clean of the decarb (if that is what it is) and true up the edges before I go to work?

 

[noseoil]

The 5160 I got was good to go once it was laid out. Just give it a try & see how it works. Should be plenty soft already.

 

[Mark Knapp]

Yes that's mill scale. Just treat it like any other annealed steel.

 

[pastormarty]

Thanks guys.

 

[Drew Riley]

If there's mill scale on it, there's a chance that it has been annealed, but chances are just as likely that it's just regular hot rolled and may have some hard spots throughout. If the ad didn't specify annealed, I'd be skeptical.

Cold rolled will almost always be annealled afterwards, because the rolling process makes it brittle, but it also gives it that shiny surface, not to mention, the scale is typically pickled off before rolling anyhow. Industrial annealing is almost always done in sealed furnaces with inert gas pumped in to eliminate oxygen and thus prevent scaling. However, it's not outside the realm of possibility that hot rolled steal would be annealed as well, with the scale layer left as is, if the order were to call for it.