I was looking at Crucible's heat treat data for CPM 154 (link) and could not figure out the recipe I needed for a slip joint that I'm going to make. If I want to keep 5 points of hardness difference between the blade and the back spring (to prevent galling) I can easily do it with 1900F and no cryo (blade 59Rc and the back spring 54Rc). If I want to convert any retained austenite I need to sub zero quench, but can not find a tempering temp to use to get the back spring down to 54Rc. For knife blade thickness, is 1 hour soak time still the correct time to use? Thanks in advance.
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CPM 154 heat treat question
- Thread starter Lo/Rez
- Start date
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- Apr 20, 2005
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You better keep it a lot different than 5 hardness points. The difference between a blade and the spring is like
61-62 Rc on the blade, and 48-49Rc on the spring. 1145 degrees for the spring should get you pretty close. I
usually do them 2 hours twice just like blades but a different temperature.
Ken.
61-62 Rc on the blade, and 48-49Rc on the spring. 1145 degrees for the spring should get you pretty close. I
usually do them 2 hours twice just like blades but a different temperature.
Ken.
Last edited:
Your tempering temperature will depend on your austinizing temperature. I agree that upper 40's is what you would need for a back spring. Follow this linkfor heat treating data for 154CM
http://www.simplytoolsteel.com/CPM-154-stainless-steel-data-sheet.html
Jim A.
http://www.simplytoolsteel.com/CPM-154-stainless-steel-data-sheet.html
Jim A.
Thanks for the info. I will definitely be doing the blades at 61-62Rc. If I heat treat the blades at 1950F (1 hour) and plate quench followed with sub zero (30-60 minutes) and two 2 hour tempers at 400F I should get approx 62Rc. I'm guessing for the back springs I should heat treat at 1900F for 1 hour, plate quench and then temper at 1135F-1145F for the correct Rc. Is that correct?
- Joined
- Apr 20, 2005
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You should come close on the draw for 61-62. You are not as concerned with galling
(if your blade tang and inside your spring are polished) as you are with a spring breaking
with the .040 rise you will have to keep the tension on your blade tang. Once you have
the spring tension right and the tang and inside the spring polished don"t ever put it together
again without oil or grease in the joint.
Ken.
(if your blade tang and inside your spring are polished) as you are with a spring breaking
with the .040 rise you will have to keep the tension on your blade tang. Once you have
the spring tension right and the tang and inside the spring polished don"t ever put it together
again without oil or grease in the joint.
Ken.
Last edited:
Thanks Ken. I started with AEB-L yesterday and decided today to try CPM 154 as there are a lot of experienced people working with it in slip joints and I could only find a tiny bit of info for heat treating springs in AEB-L. I've never worked with CPM 154 before so that I'm looking forward to that.