SM-100 at 70HRC without heat treat?

[shqxk]

The folder blade was cut by EDM but it seems to be super difficult to grind even with ceramic belt or hand sanding so it was send to commercial HT company to get rockwell test and it came out at almost 70HRC from 3 times test which really surprised me.

It still hasn't get any heat treatment beside get into low temp salt at 400F for an hour for straightening when it was still a sheet. Anyone have an idea about this?

 

[Sam Dean]

That material (SM-100) is not capable of 69/70Rc, even under the best circumstances. Since it's not a steel, "heat treating" means it gets age hardened to a max around 62Rc.

Did you get it from SB Specialty Metals, and did you get the material certification with it?

 

[shqxk]

That material (SM-100) is not capable of 69/70Rc, even under the best circumstances. Since it's not a steel, "heat treating" means it gets age hardened to a max around 62Rc.

Did you get it from SB Specialty Metals, and did you get the material certification with it?

Yes, it was bought from SB Specialty metals. This piece is the last one they will sold AFAIK.

From the datasheet 62rc is the max hardness which make me wonder why it tested this high.

Actually I plan to HT it at 1800F for 25minutes then plate quenching but right now I'm not sure if I really need any further HT.

I think I better have it get hardness test from others tester soon to confirm this.