Patience grasshoppah' It's 1095

Dealer - Purveyor
I've been hesitating about posting this for a while but it's caused me enough grief that maybe I can save someone else the same. When I pull O1 out of the quench oil and check hardness, it's 65 - on the nose - every time. I could almost use the stuff as a test block.

1095 is a different animal. As many of you know, I've struggled with it for years. Out of the oil RHC 55. Arrgh!!!! Do it again - and sometimes again/again.....

A few weeks back, I came in grumbly and Marilyn asked me to show her what was eating at me. Marilyn is pretty literate about HT, so maybe an extra set of brain cells would help. I took her out to the shop. The blades are ALDO 1095 - stock removal - I coat in Turco to prevent decarb - precision kiln - agitated quench tank with P50 - and I'm pretty quick and smooth into the quench which is right beside the kiln. Out of quench at hand warm (about 45 seconds) and over to the Rockwell tester. RHC 53. Aargh!

"What is your test block reading?" Marilyn says. I roll my eyes. I'm 13 points shy of where I should be - that isn't calibration. "Humour me." She says. The test block is 60.9 and the analog guage sure looks a lot like 61. Hard to beat that.

"Now the blade." She says. I roll my eyes again. I know I should average 10 hits for a good RH, but this degree of discrepancy isn't about averaging. "Humour me." she says. Hit the blade again and look! WTF??????? RHC61! It's gained like 8 points since I tested it 10 minutes ago. She smirks, figuring she has a win. :31: 1095 at RHC61 is hardly a win. :58:

She heads back to the house and I'm scratchin' my head. Maybe most of the blade failed at 53 and on the second test, I just nailed a big ugly carbide or something. Lets try a number of tests to see what kind of range I get. 66 - 66 - 66.5 - 66. So now, 20 minutes after quench, my "failed" HT is bang on where it should be.

I've only done three more since that one, but the results have been pretty much the same - way too soft right out of the quench and "harder than a woodpecker's lips" (love that) after 20 minutes.

I wonder how many guys have had a file 'bite' that would have skated if they'd waited. I wonder how many times I re-did 1095 blades that didn't need to be redone.

Just thought I'd share.

I have found the same thing. I always let blades set for 15-30 minutes before checking them. I found this out by accident. I checked a blade as soon as it was cool enough to hold with bare hands and a file cut into it like it was still annealed. I walked away shaking my head to do something else that had to be taken care of and came back about 20 minutes later and the file skated like it was supposed to. I had this same discussion with another forum member about a week or 10 days ago and he has made the same discovery.

Doug Lester

Well-Known Member
HUMMMM...Something allowing retained austinite to convert when allowed to cool fully to ambient temperature? Just a guess.



Well-Known Member
Yes. 01 is even slower to make the conversion. I can straighten warp in 01 for five minutes or more bare handed. Let it sit five more minutes and it will likely break if pressured too much. Martensite does not begin formation until around 450°. When it starts, it starts very fast, but finishes slow, and allows some austenite to not convert. Below 400° you can water quench and gain a tad more martensite, and after each temper do the same and gain more. You can never get 100%, but you can close the gap a bit.