So far all my knives have been built from 01 tool steel.
My first attempts at heat treating resulted in usable knives but as time went by and I acquired more experience and equipment my heat treat inevitably improved.
I used to harden my early blades in a charcoal forge, quench them in vegetable oil and temper them in the house hold oven.
Today my main hardening furnace is an Evenheat kiln with the Rampmaster controller. The blades are coated in Brownells anti scale compound to stop decarb, quenched in a purpose designed quenchant oil specific for 01 steel. The knives are tempered in a PID controlled oven.
All knives are Rockwell tested in several places to ensure they are where I want them to be.
My tests reveal that 01 steel benefits from a good soak at temperature to achieve full and consistent hardness. This allows all the carbides to melt into solution.This can be done with great accuracy in the Even heat kiln. The blades are heated to the lower end of the critical range. Too hot and you will get grain growth. We don't want that! Too cool and you won't achieve full hardness. Don't want that either:)
The blades once quenched are tempered soon after, and given a sufficient amount of time to elapsed to allow for the transformation to Martensite to occur whilst ensuring the knives do not become too cool. The blades are tempered upto three times to ensure a good temper allowing for them to cool slowly between each cycle. Minimum temper times of two hours for the first temper cycle.
My heat treatment has been an ongoing process of improvement by trail and error, testing and measuring to the point where I have not been able to get any better results than what I am now achieving.
I know a lot of knife makers will read this in the hope of gaining a snippet of info but the best advice I can give is to make your own tests. To get best results you really need a digitally controlled kiln and a Rockwell hardness tester, then do your tests to confirm you have got it...!
My first attempts at heat treating resulted in usable knives but as time went by and I acquired more experience and equipment my heat treat inevitably improved.
I used to harden my early blades in a charcoal forge, quench them in vegetable oil and temper them in the house hold oven.
Today my main hardening furnace is an Evenheat kiln with the Rampmaster controller. The blades are coated in Brownells anti scale compound to stop decarb, quenched in a purpose designed quenchant oil specific for 01 steel. The knives are tempered in a PID controlled oven.
All knives are Rockwell tested in several places to ensure they are where I want them to be.
My tests reveal that 01 steel benefits from a good soak at temperature to achieve full and consistent hardness. This allows all the carbides to melt into solution.This can be done with great accuracy in the Even heat kiln. The blades are heated to the lower end of the critical range. Too hot and you will get grain growth. We don't want that! Too cool and you won't achieve full hardness. Don't want that either:)
The blades once quenched are tempered soon after, and given a sufficient amount of time to elapsed to allow for the transformation to Martensite to occur whilst ensuring the knives do not become too cool. The blades are tempered upto three times to ensure a good temper allowing for them to cool slowly between each cycle. Minimum temper times of two hours for the first temper cycle.
My heat treatment has been an ongoing process of improvement by trail and error, testing and measuring to the point where I have not been able to get any better results than what I am now achieving.
I know a lot of knife makers will read this in the hope of gaining a snippet of info but the best advice I can give is to make your own tests. To get best results you really need a digitally controlled kiln and a Rockwell hardness tester, then do your tests to confirm you have got it...!