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JC in SC
08-27-2010, 03:58 PM
Does anyone have tempering data for ~0.100 thick CPM154 for use as a slip joint spring? I got heat treat data and blade tempering info from Tracy's site. Now I just need spring temper info.

Thanks,
JC

Rusty McDonald
08-27-2010, 04:16 PM
Yep I got it.
Oops it didnt copy sry
1200* temper for 2 hours 1 time, works for me
http://evenheat-kiln.com/knifeovens/technical/heattreatinginformation/ghtd.pdf

BossDog
08-27-2010, 06:37 PM
shoot for 43 to 44RC on a folder spring

JC in SC
08-27-2010, 08:48 PM
Thanks for the responses guys.


Yep I got it.
Oops it didnt copy sry
1200* temper for 2 hours 1 time, works for me
http://evenheat-kiln.com/knifeovens/technical/heattreatinginformation/ghtd.pdf

Hey Rusty,

Do you heat treat per those guidelines as well? I'm wondering what the differences would be between that profile and the one Tracy has posted (1900F for 15 mins vs. fast ramp to 1450F, hold for 10 mins then fast ramp to 1850F for 30 mins). If these guidelines provide good results and work for you every time, I might just follow them. I'm not planning any cryo at this time either. How soon after heat treat do I need to temper?

Thanks,
JC

Rusty McDonald
08-27-2010, 09:39 PM
I like the pre heat to take out the stress before you go to the treating heat. I start mine at 1500* for 10 min though then to 1900* for 20 min for slipjoints is plenty.

JC in SC
08-27-2010, 09:51 PM
Cool. I'll try that profile on Monday then. Thanks.

JC in SC
08-30-2010, 03:34 PM
Okay, here are the initial results. Fast ramp to 1450F, hold for 10 minutes. Fast ramp to 1900F, hold for 20 minutes. Plate quench between two 1" copper plates in an arbor press while blowing shop air between plates. Depending on location, the spring measured 58 to 60.2 Rc and the blade measured 59.7 to 60.2 Rc. I tempered the spring for 2 hours at 1200 and it dropped to 40 Rc:( The blade will be out of the second 2-hour, 400F temper cycle in about 15 minutes. I was shooting for the 43 to 44 like Boss said on the spring, which I obviously missed. I'm curious how badly a spring at 40 will compromise the function of the spring. Any thoughts there?

Thanks,
JC

JC in SC
09-01-2010, 02:51 PM
I repeated all of these efforts adjusting here and there based on the initial results.

Heat treat: Fast ramp to 1425F, soak for 10 minutes. Fast ramp to 1925F, soak for 30 minutes. Quench between two 1" thick copper plates while blowing shop air in between. Both pieces measured 61.x Rc.

Spring temper: Inserted into furnace preheated to 1150F, set point adjusted to 1100F and soak for 2 hours once. Spring measured 47.3 Rc.

Blade temper: Inserted into oven preheated to 400F and soak for 2 hours. Cool to room temperature and repeat. Blade measures 59.3 Rc.

I think this isn't half bad for my second attempt. It definitely helps to have access to nice furnaces and a hardness tester. Thanks for helping out.