Looking for a tempering chart

R

Railrider1920

Joined
Dec 14, 2010
Messages
403
While I was reading some threads in a search, I came across a tempering chart someone had posted. I was basically like this:

300 (2) 1 hr cycle = 60Rc
350 (2) 1 hr cycle = 57-58 RC
400 (2) 1 hr cycle = 55-56
450 (2) 1 hr cycle = 54-55 RC

Or something along those lines. Does anyone know where to find a chart like this? Right now I'm mainly working with 1084 stock, so I'd be interested in one that would apply to that steel, but one for others would be cool. Or would they all use the same when tempering?

Thanks,
Rob
 
cashenblades.com. Go to the bottom and click on bladesmithing information.
 
Hmm the 1095 tempering info seems high to get to the mid to low 50's. Is that correct?
 
Here is the main page for those wanting to see what we are talking about:
http://www.cashenblades.com/heattreatment.html

The temperatures seem high, but for fully hardened 1095, are about right. Most knife blades aren't fully hardened, which takes a lot more than the way we do it. Fully hardened 1095 will get to Rc 65-66. Most as quenched blades are more like Rc-63-64.

Charts, like Kevin's, are usually empirical. The real world is rarely as tightly controlled.
Compare this to the MPG that the charts say a car gets. With a test driver, on a closed course, with all the gauges and other test devices hooked up....yes, some get 47 MPG. But on Santa Monica Blvd. in rush hour....more like 30MPG should be expected.

Most people greatly under temper their blades. 350F for two hours might take a little out of your 1095 blade, but it won't make a properly hardened blade Rc58-59. The main reason that someones 1095 blade with a 350F temper tests at Rc58-59 is that it never got much beyond Rc 61-62 when quenched. I use 400-425 for most 1095 blades...and get around Rc60-61. 450F gets me Rc 58-59.
 
I'll add a story to illustrate what Stacy said. Consider blades of 1080 heat treated in a digital kiln, austentized at 1475 x 5 minutes. When I quenched in vet grade mineral oil and tempered at 425, I got 60 RC and a nice edge. When I finally got some DT-48 quench oil from Maxim, I quenched and tempered at 425 and got 61.5 RC and a chippy edge. I had to bump my temper up to 450 to get 60 and nice, once I started using an oil that got better martensite conversion.
 
I can attest to the same with 1084FG. When I went from Canola to HQ-K I had to bump my temper from 400F-415F to 450F. I temper 1095 at 475F for larger blades.
 
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