Author Topic: Cross cut saw for knife blade  (Read 2045 times)

Offline Nhgrants

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Cross cut saw for knife blade
« on: January 07, 2019, 02:21:47 AM »
I have an old broken 2 man saw and I made one knife
Blade from it.  This blade would not hold an edge.
My first thought was that I did not heat treat it very well.
As the blade is meant to be sharpened with a file, is it likely
That this material will not be hard enough for the file to skate
Off rather than digging in?  If that is the case, can steel this
Be sharpened to a usable edge? Thanks

Offline rich pierce

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Re: Cross cut saw for knife blade
« Reply #1 on: January 07, 2019, 02:27:20 AM »
Big old crosscut saw?  I have used this steel to re-face frizzen sand gotten it hard as glass. How are you quenching it?
Andover, Vermont

Offline Nhgrants

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Re: Cross cut saw for knife blade
« Reply #2 on: January 07, 2019, 03:45:42 AM »
I think I quenched it in cooking oil.  May be I did not get it hot enough.




Offline rich pierce

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Re: Cross cut saw for knife blade
« Reply #3 on: January 07, 2019, 05:22:38 AM »
I used brine.  I always check with the “file skid test” and change things up in hardening if a file can cut it.
Andover, Vermont

Offline jcmcclure

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Re: Cross cut saw for knife blade
« Reply #4 on: January 07, 2019, 04:32:21 PM »
I think I quenched it in cooking oil.  May be I did not get it hot enough.

Do a process of heating the blade to non magnetic and allowing to slowly cool to room temp. On the quench bring to non magnetic and give canola oil a try.

Also heat your quench oil up before you quench your blade. Just quench a piece of scrap material and that will be fine to heat your oil.

Offline rich pierce

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Re: Cross cut saw for knife blade
« Reply #5 on: January 07, 2019, 06:49:49 PM »
It’s worthwhile to take a scrap piece of any unknown or recycled steel through the heat treat process and test it before making a blade.
Andover, Vermont

Offline WH1

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Re: Cross cut saw for knife blade
« Reply #6 on: January 07, 2019, 09:37:37 PM »
I think I quenched it in cooking oil.  May be I did not get it hot enough.

Do a process of heating the blade to non magnetic and allowing to slowly cool to room temp. On the quench bring to non magnetic and give canola oil a try.

Also heat your quench oil up before you quench your blade. Just quench a piece of scrap material and that will be fine to heat your oil.

Concur on the normalizing process I heat to non-magnetic then let it cool to black two times before quenching.
I have a small cooking thermometer I use to test the canola oil prior to quenching.  I heat the oil with scrap steel between 120-140 degrees.  Also use new canola oil.  I change mine frequently about every 3 months depending on the number of blades I am working or how much the dog drinks when I forget to put the lid on.  after a while it loses its viscosity I guess.  The oil not the dog.

Offline Greg Pennell

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Re: Cross cut saw for knife blade
« Reply #7 on: January 07, 2019, 11:26:32 PM »
I just hate it when my dog loses his viscosity... :o

Greg
“Let your gun therefore be the constant companion of your walks” Thomas Jefferson

Offline jcmcclure

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Re: Cross cut saw for knife blade
« Reply #8 on: January 08, 2019, 05:33:12 AM »
I think I quenched it in cooking oil.  May be I did not get it hot enough.

Do a process of heating the blade to non magnetic and allowing to slowly cool to room temp. On the quench bring to non magnetic and give canola oil a try.

Also heat your quench oil up before you quench your blade. Just quench a piece of scrap material and that will be fine to heat your oil.

Concur on the normalizing process I heat to non-magnetic then let it cool to black two times before quenching.
I have a small cooking thermometer I use to test the canola oil prior to quenching.  I heat the oil with scrap steel between 120-140 degrees.  Also use new canola oil.  I change mine frequently about every 3 months depending on the number of blades I am working or how much the dog drinks when I forget to put the lid on.  after a while it loses its viscosity I guess.  The oil not the dog.

You are right oh the oil needing changed. I had to change an old batch out tonight because I was quenching 6 blades. Just wasn't happy with the old oil on the first couple of blades.