heat treating in a forge

[Jeff Faria]

So today i tried heat treating 1095 in a forge. temperature stayed about 1480f for the first couple minutes then it went up to 1600 then down to 1400 managed to get it back to 1500 at the ten minute mark then i quenched it in oil at 130f chevron70 oil from jantz.this is the third time i have heat treated tis knife i put clay on the spine to create a hamon line and that looks very good just like i planned it but there is a spot near the tip that is kinda off colour. I only tempered the knife after each heat at 350f for two hours times 2 file seems to skate across hardened areas sorry no picture knife in oven now. I will get a better look at it tomorrow when i clean it up some and etch it see how it looks but would love to hear what you guys have to say

 

[Stacy E. Apelt - Bladesmith]

Not sure what the question is.

I would do the tempering at much higher temperature. Start at 400F and test the edge on a brass rod for chip/roll. Raise it to 425F if it chips, and again to 450F if it still is chippy at 425. I normally use 425F or 450F ( depending on use) as my temper and don't bother testing, as this has always got good results for me. I only use a 350-400F temper for very hard edge slicers like a manage-ba. These are used veru carefully, and the chippy edge isn't a problem.You can still re-temper the blade.


People have a feeling that the difference between a 350F and 450F temper is many points of hardness. Actually, it is only a few hardness points drop, but a large increase in toughness.
If you will look at the below chart, you will see that the hardness drops from Rc 64 to Rc 60 in a 300F temper vs a 500F temper. That is only a 6% loss. Rc 60 is higher than normal on most user knives. However, the Charpy impact curve shows a rise from about 12 to 40. This is a 300% increase in toughness.
http://www.bing.com/images/search?q...5251d4898c0e7204fc8bfee1a7ea59ddo0&ajaxhist=0