# Heat treat headache



## robert flynt (Jan 24, 2015)

New batch of ATS34 did not respond properly to heat treat, all blades to soft according to RC hardness tester. Checked calibration of hardness tester and checked kiln set points and temp. at the set points with Omaga Meter. Found temps. holding higher than set points and and controller was allowing temp. to over shoot and was taking way to long to come back down to set point. Adjusted controller to hold at proper temp. adjusted ramp speed to allow temp. to climb as fast as possible to within 180 deg. of set point then slow down to a rise of 500 deg. per hr. Re foil wrapped the blades and tried again. blades still not hard enough. Ruled out wrong temps. Suspected steel! Found by trial and error proper hardening temp. for this batch of steel is was 120 deg. higher than normal. Two days later and lots of head aches. Such is life!!!


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## NYWoodturner (Jan 24, 2015)

Thats a great catch Robert. Do you mind if I ask where you bought it? I ask because I just acquired some ATS34 for myself and Tom. Can't help but wonder if it could possibly be from the same source?

Reactions: Agree 1


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## Schroedc (Jan 24, 2015)

Ouch, that is a headache to run into!


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## robert flynt (Jan 24, 2015)

NYWoodturner said:


> Thats a great catch Robert. Do you mind if I ask where you bought it? I ask because I just acquired some ATS34 for myself and Tom. Can't help but wonder if it could possibly be from the same source?


I got it from Admiral Steel. I use a uniquely different heat treat than other knifemakers for my ATS34, 154Cm and CPM154Cm. I heat treat at 1850 deg. for 1hr. 45min. then make my 1st draw at 880deg. and my 2nd draw at 860deg. Normally I get a non chippy RC 60 +or - 1/2 . The more standard higher temp. and shorter hold time might have worked fine but a lot of those recommend a cryo between draws and my formula does not require this.


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## Tclem (Jan 24, 2015)

I don't know what you just said but I agree with you

Reactions: Agree 2 | Funny 2


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## Foot Patrol (Jan 24, 2015)

Sorry to hear your problems with the heat treat. I hope you get it worked out.

I am still doing simple carbon blades and use my forge to heat treat.

Reactions: Thank You! 1


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## NYWoodturner (Jan 25, 2015)

Well thats the same place I got if from. Really good info and thanks for the heads up.


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## robert flynt (Jan 25, 2015)

NYWoodturner said:


> Well thats the same place I got if from. Really good info and thanks for the heads up.


I wouldn't worry to much. They sell a lot of steel and are a reputable company. I still have some of that steel left and intend to try a different heat treat on some fresh steel and if I have bad results I will talk to Vice President of sales Terry Summers, who I know real well.

Reactions: Like 1


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## NYWoodturner (Jan 25, 2015)

I get most of my steel from them and have had nothing but excellent service and product. I'm not at all worried but wanted Tom to have the heads up if that were the case. I am going to try your heat treat recipe  Any others you care to share


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## Molokai (Jan 27, 2015)

Thats great info. Looking forward to hear what will come from this. Now to translate all those Fahrenheit to Celsius


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## robert flynt (Jan 27, 2015)

NYWoodturner said:


> I get most of my steel from them and have had nothing but excellent service and product. I'm not at all worried but wanted Tom to have the heads up if that were the case. I am going to try your heat treat recipe  Any others you care to share


That one is the only one radically different from what what most knifemakers use. You can find at least half dozen different heat treats for ATS34 but I prefer this one. One thing I would recommend, is to check hardness before the first draw (temper). If you don't have at least RC62 your not going to get the RC60 I prefer. Don't waste your time just reheat treat the blade.

Reactions: Informative 1


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