View Full Version : Difficult Heat Treating

06-19-2011, 11:14 AM
I've read various things over the last few months and talked to a couple of knife makers about heat treating.

Something that often comes up is that 1084 is easy to heat treat and others are more difficult.

What makes one steel harder to heat treat than others?

Each has their own formula....put in oven at certain temperature, ramp up to another temp, hold for so long, quench by air/oil/plate, temper, cryo perhaps, etc.

I know that's simplistic, and not all inclusive. But, it's close, right?

Anyway, given doing the whole heat treat with a programmable kiln and all of the other necessary bits, what would make one more difficult than the other?

Is it more that a steel like 1084 can be done without the programmable kiln?

James Terrio
06-19-2011, 11:56 AM
Is it more that a steel like 1084 can be done without the programmable kiln?

Yes. It's possible to get reasonably decent results with 1084 by simply heating it to non-magnetic and quenching, because it's not much more than iron and carbon. Other steels with more alloying elements in them require more precise temps and longer soaks at those temps, plus a more specific quench to get to a fully-hardened state.

Of course even the very simplest steels will benefit from more detailed Ht procedures.

Doug Lester
06-19-2011, 03:47 PM
As James said, each steel has it's own characteristics. In general, the more complex tha alloy the more complex the heating requirements. Carbon content also figures in. Some of the moderate carbon content simple steels like 1060, 1070 are very simple to heat up for quenching (austinizing) but the austinite will start changing to various conversion products rather rapidly so you have to have a more agressive quenchant to convert it to martinsite. Steel metallurgy is a real study of it's own but is not required to make a good blade. You can cookbook the process if you pretty much stick with the standard formula for heat treating a specific steel. This craft is full of compromises.


06-19-2011, 08:58 PM
Thanks. What I figured, just want to make sure I really know what I think I know as I move forward.