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jylong_away
08-17-2010, 05:12 PM
Hi,

Have been reading the various maker tutorials available(while waiting for my first knifemaking supplies to arrive!).

I've noticed that some makers heat treat the knife blanks before grinding the primary bevel, and some heat treat after.

Are there any benefits or problems with either approach to the timing of the heat treat?

With my limited knowledge, the bevel would be a fair bit harder to grind on a heat-treated blade, so grinding bevels before HT seems an easier option?

Thanks for the help!

Dave

BossDog
08-17-2010, 05:38 PM
Some heat treat a blank before grinding so any warpage from the heat treat is ground out. You want to make sure all the holes are drilled in advance of heat treating and when you are grinding, keep it below 300 to 350F (steel depending) so you don't soften it up. Basically if you are grind it and the blade turns blue or purple, you have gone way past that 350F mark.

It's fairly common practice for folder makers to harden before grinding but not so much fixed blades. Bark River Knives puts out 20,000+ knives a year and they are ground hardened by hand.

jylong_away
08-17-2010, 06:26 PM
Some heat treat a blank before grinding so any warpage from the heat treat is ground out. You want to make sure all the holes are drilled in advance of heat treating and when you are grinding, keep it below 300 to 350F (steel depending) so you don't soften it up. Basically if you are grind it and the blade turns blue or purple, you have gone way past that 350F mark.

It's fairly common practice for folder makers to harden before grinding but not so much fixed blades. Bark River Knives puts out 20,000+ knives a year and they are ground hardened by hand.

I'm toying with doing my first attempt with hand tools (files, etc). would it then be advisable to grind the blades before HT? Or is it still relatively easy to hand-file hardened steel?

When you say that BRK hand grinds hardened blades, do you mean with hand-files, etc, or hand ground on a belt grinder?

Bob Warner
08-17-2010, 06:40 PM
You will not be able to hand file hardened steel.

The hardened blades are ground on a grinder like a KMG. If you don't have a belt grinder you should grind before heat treat.

jylong_away
08-17-2010, 07:07 PM
You will not be able to hand file hardened steel.

The hardened blades are ground on a grinder like a KMG. If you don't have a belt grinder you should grind before heat treat.

Thanks - I guessed as much ;)

My plan is to start by hand, and then get a basic grinder if it looks like I'm not getting anywhere. Have already scoped out a decent hobby-level grinder. Who knows, though - hand tools might just do it for my first try?

Dave

James Terrio
08-18-2010, 01:00 AM
Who knows, though - hand tools might just do it for my first try?

Yup! Good files like Nicholson or Simonds brands will remove/shape unhardened steel just fine, at least for bevels and such. Draw-filing works very well. Clean your files often with a file card (might cost a whole dollar or two) to prevent little bits of steel making deep scratches that will make you say bad words.

I feel pretty strongly that the first power-tool to buy is a basic drill press that can be slowed down so you don't burn up bits. Drilling around your profile and "connecting the dots" with a hacksaw saves a lot of time. And getting the holes for pins etc square is pretty easy with a drill press, not so much with a hand-held drill.