440C Finish

D

Diamond G Knives

Well-Known Member
Hey guys

Just finishing an order for a Santoku in 440C. Ive never used stainless before and will be sending this off to be HT'ed. A couple of questions.

1.) Is the cryo treatment worth the effort?
2.) What finish should I go to before HT?
3.) How thick should I leave the edge prior to HT to prevent warping?

Thanks and God Bless
Mike
 
Mike
In my experiance cryo is very good for 440-c
On finish you can do about 90% finish I often go to 600 hand rubbed.
You can go to about .020 on the edge if you grinds are even.
With a good H/Ter your blade should return looking almost like you sent it with very little oxidation.
Stan
 
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I agree, and I also recommend the cryo treatment. It will increase the hardness while still giving fexibility. Edge holding should increase about 15%-20% Frank
 
I just HT twelve (12) 6.5" 440C knives today. I take the edge to around .040 with a 120 grit belt prior to HT. 120 grit finish on the flats as well. From the oven to the aluminum plates for quench. Temper once, liquid nitrogen overnight, temper again then cleanup.

This batch will get a stone washed finish: 400 grit on the flats, Scotchbrite medium and fine on the bevels, 80 grit bead blast then the vibratory bowl for around 2 hours.

BC
 
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Bill Coye said:
I just HT twelve (12) 6.5" 440C knives today. I take the edge to around .040 with a 120 grit belt prior to HT. 120 grit finish on the flats as well. From the oven to the aluminum plates for quench. Temper once, liquid nitrogen overnight, temper again then cleanup.

This batch will get a stone washed finish: 400 grit on the flats, Scotchbrite medium and fine on the bevels, 80 grit bead blast then the vibratory bowl for around 2 hours.

BC
Click to expand...

And a partridge in a pear treeeeeee!:D
 
Wonder what Turtle Doves would taste like heat treated and stone washed. :eek: Can't wait to see the Santoku finished. Will be watching for pics.2thumbs
 
Always HT doves at 350 degrees and soak for 10 minutes. You should quench in a good white gravy about 160 degrees get the proper effect of such a delicate Heat treat method.
 
Ive been told that you can do a cryo treatment with dry ice and either acetone or kerosene. Could anyone explain the process? Also, I have seen reference to tempering after cro treatment. Can anyone give me the details on this? As I said, Im not a stainless guy!

Thanks and God Bless
MIke
 
Mike
I use quench plates to room tempand then into cryo for 6 hours then do my temper cycles.2 X 375 deg for 2 hrs.
The dry ice method is to get a couple of blocks of dry ice bust them up with a hammer and mix with enough acetone or kerosene to make a slurry.Let them sit in the slurry till all the dry ice has evaporated.
Stan
 
FWIW my local welding supply place sells dry ice in pellet form so you don't have to smash it up to make your slurry.
 
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