1084 heat treating

T

tony moyer

Joined
Feb 23, 2003
Messages
102
I just got done breaking a blade made from 1084 to see what the grain size was and it was just like a drill bit in color and size.I heat treated with a torch along the edge of the cutting edge and quenched the whole blade three times.The blade bent perfect along the spine but snapped where it was hardened.

I tempered it at 350 deg three times.At what temp should I start,and will a 1084 blade even withstand a bend test.

Thank you
Tony
 
Tony, 1084 will work as a spring with the correct spring temper (about 700 deg) but a spring will not hold an edge. I think your blade was still a bit hard at 350 deg temper. It should have been a good edge holder but wouldnt have broke at say 375-400 3 times at one hour each. There are so many variables that each maker will need to draw his own conclusions from his own testing. 1084 is a great blade steel and will easily pass the American Bladesmith Society bending test. My mastersmith test blade is a 1084/15n20 damascus. Tempered at 395 deg. Hope Ive answered your question.
 
Tony, Bruce is correct, by tempering 1084 at 400dgr. for three one hour sessions your blade will have an edge hardness between 56-58 Rc and will take a 90dgr bend. I heat treat spring steels all the time and only on 2"/shorter caping blades do I temper below 395dgrs. See my website at www.bearclawknives.com Lee Oates
 
In my limited experience with 1084 I've experienced chipping on small thin knives tempered at 375 degrees F so I have since begun tempering my 1084 blades at 400-410 degrees F. I've heard some makers recomend up to 425 degrees F. If it's a big beefy blade, however, with a strong convex grind you can probably get away with the 375 degree F temper (for heavy use that is, not necessarily the ABS test). I believe (someone corect me if I'm wrong) that Gregg Covington tempers his thick convex ground battle blades made from 1084 at around 375 degrees F. There was a great thread within the past year that discussed the whole edge geometry/tempering tempereature/intended use thing. As usual in knifemaking you have to make a lot of compromises for a general use knife and the ABS test really is designed to test a smith's ability to manage various aspects of forging/heat treating in order to make a knife to accomplish a specific task.

Am I offcially rambling now? :D
 
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