budget knifemaking from an old file

[Mike Ameling]

I've got several lengths of cromwell O1 (and old files for that matter) in the shed and to be honest it's the thought of the heat treatment that puts me off.

Yes, the heat treat is the really tricky part. Once you get into the higher carbon steels (like above 1085) or the specialty alloy steels, you need to be a lot more precise in the temps and quenching to get an optimum heat treat on a knife blade. If you are using something like 1095 carbon steel, at one point you have only 1 second to cool the blade through a certain temp range - to get that optimum heat treat. So a very controlled heating/cooling environment is almost required.

But you don't have to get that "optimum" heat treat to have a using knife. Just letting most tool steels "air cool" will give you a usable knife. The cutting edge probably won't hold up as well in use, but that just means sharpening it a little more often.

That's why I like those old lawn mower blades. They are generally made from 1084 carbon steel, or 5160 alloy steel. They both are far more forgiving in the heat treat.

Good luck on you project.

Mikey - that grumpy ol' German blacksmith out in the Hinterlands
- who knows several professional knife makers

 

[wildrover]

It's a half gas canister, with a length of piping into the bottom, then connecting a foot pump onto the end of that to provide a draught. the charcoal gets pretty hot, the dustbin lid helps to see the colours of the metal a bit and shield things. I have a magnet on a stick to check when the steel is non magnetic, and a tin of veg oil nearby. Once its cleaned up after hardening, I use the kitchen oven to take some of the hardness out..

Thanks for the photos John.
It looks quite straight forward
I've got some time off organised, if shmbo doesnn't have too many diy duties for me to do (or finish ) I might actually get a chance to gert on with this

Yes, the heat treat is the really tricky part. Once you get into the higher carbon steels (like above 1085) or the specialty alloy steels, you need to be a lot more precise in the temps and quenching to get an optimum heat treat on a knife blade. If you are using something like 1095 carbon steel, at one point you have only 1 second to cool the blade through a certain temp range - to get that optimum heat treat. So a very controlled heating/cooling environment is almost required.

But you don't have to get that "optimum" heat treat to have a using knife. Just letting most tool steels "air cool" will give you a usable knife. The cutting edge probably won't hold up as well in use, but that just means sharpening it a little more often.

That's why I like those old lawn mower blades. They are generally made from 1084 carbon steel, or 5160 alloy steel. They both are far more forgiving in the heat treat.

Thanks for the advice Mike, You know how it is best intentions and all that....
I suspect that once I actually get started I'll be fine it's just that first step.

now that I think about it I think there is an old lawnmover in the shed

 

[sticks65]

Nice job...............

 

[whittle]

Beautiful knife there.As for the 2p's..pre 1970 coins are all copper.Just thought you might like to know!

morning,

you'll find pre 1992 coins made of an alloy that is high in copper, cut costs after 1992 with the steel coins. you can check because all pre 1992 coppers are non-magnetic.

 

[Mooseman1]

lovely knife mate and great pics.