How To SS post HT clean - newbie error?

M

Markliep

Joined
Apr 4, 2017
Messages
3
Hi wise ones

SS newbie Q - I recently received some CPM154 blades back from a commercial heat treater & have spent a boring few hours & about 2 belts per blade to get these puppies polished free of whitish scratch-like deposits.

Am guessing my error (I usually work with high carbon steel) was to not polish the blades prior to sending them out, however I'd like to be certain that my assessment's actually correct in case anyone else asks me for SS in the future so I'm better prepared ....am not a fan of endless time spent polishing :(

Thx for any & all responses - M

BTW apologies for no pic to show this but there seems to be no simple way to upload as in the pre-Photobucket days
 
What Grit did you stop at before sending to heat treat?
 
Yes, good question. I always go to 280+ hand-sanded before heat on stainless. Then removing the oxide layer is a snap with some fresh 280 or 360. Lots of carbides in hardened CPM154 make it very wear resistant.
 
I grind my 154cm blades to an a160 gator before heat treat, and pick back up with an a100 gator after. From then work down however I'd normally polish something.
Grinding to 120 or 220 before, and going to a 220 or 320 after would work as well if you don't use structured belts
 
Mucho Thx guys - have learned something new that'll hopefully make life easier for the next time I go with SS - M
 
I use a lot of CPM 154 for my knives and I remember this discussion a few years ago when some of he knife makers suggested nearly finishing their blades before heat treat and I have been doing that since. My blades look finished except that I leave about .040 edge thickness before heat treating ands I always request they be foil wrapped before treat. I have just received a dozen blades back from Paul Bos heat treat and they only need to have the edges taken down and blended to the grind and then final finish either high polish or satin finish. This has worked for me for several years. I might suggest that you request your blades be foil wrapped before heat and do a little more finishing prior to heat treat. Larry
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Ido t think Paul foil wraps blades at least I can't imagine that thy have the time to. I think thy use a vacuumed furnace and nitrogen purge quenching.
 
JTknives said:
Ido t think Paul foil wraps blades at least I can't imagine that thy have the time to. I think thy use a vacuumed furnace and nitrogen purge quenching.
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The last time I talked to Paul Bos he did not have a vacuum furnace.

Chuck
 
You also need to remove the mill scale if you plan to only profile and grind after heat treating. That scale will eat belts before you get to good clean steel which you discovered.
 
Paul Farner at Paul Bos heat treat does foil wrap blades and also "cryos" every blade. Larry P.S. I see "Rockwell dots" on every blade as well. I like 60 Rockwell. He gives superior service and consistent quality. LL

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Oh my bad I was thinking peters for some reasion.
 
I sometimes Finnish parts of blades up to 2500 before HT
Afterwards I only polish off the HAT scale
 
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