what grinding does to previous heat treating

jon303

jon303

Joined
Oct 12, 1998
Messages
276
Hi All,
Had a question regarding what exactly the post heat treating grinding does to a blade. Does it weaken it? I asked the Reeves at CRK if they could grind a false edge on a pre-existing Sebenza and they said they couldn't due to the heat treating. They did not elaborate. Could someone help me out? Thanks for any help,

jon

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>>>>>>>>>>>jonathan sun<<<<<<<<<<<<
www.geocities.com/Area51/Omega/9016


 
They may have some exotic blade materiel that they don't want to mess with after heat treating but in general, if they keep the blade cooled off while they grind it there is no ill effect. There are several accomplished makers who heat treat first and then grind. I would suspect that for them it's not worth the trouble. I can put a new blade in your case knife but I won't, it's not worth the trouble.:>)

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old pete
 
Frank Centofante does all of his grinding after heat treat. He uses a 20 inch wheel partially submerged in water. CRK probably wouldn't do your blade because they don't have the right equipment. Trying to grind a high alloy steel after heat treat on a high speed belt grinder would be hard. The grinding would go slowly and the steel would overheat really fast.

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Fix it right the first time, use Baling Wire !
 
depending upon the material used....you can grind just about anything after heat treat. anyone who says different is full of it... the thing you cant do is get it hot...anywhere near the tempering heat of whatever metal you are grinding and the h/t goes south....but if you have a variable speed grinder and a bucket of water....you can grind a blade from a heat treated blank. i know one well know knifemaker who does it on a daily basis.

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http://www.mayoknives.com


 
Grinding after heat treating can be done. Just be careful! I do it on knives that I'm not happy with for one reason or another and as long as you:
1. keep a bucket of water nearby,
2. make your passes quick,
3. don't lag in one spot for any length of time,
4. and dip that blade after every pass or two, you should have no problem.

BTW, 440c is the most difficult steel I've ever re-ground. To me, it seems to be quite over-heat sensitive IMO. The temper will burn off lickity-split quick if your not REAL careful with it.
eek.gif
I dip it after every pass just to be sure and have little trouble with it.
Good Luck!

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So, what IS the speed of dark?
 
hi all again,
thanks for the replies as usual
smile.gif
was wondering if anyone out there would be willing to grind a false edge (a simple one) on a large CR Sebenza, for a nominal fee of course, shipping and work to be paid by me. Thanks. Please email if interested/willing to do the work.

happy holidays,


jon

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>>>>>>>>>>>jonathan sun<<<<<<<<<<<< www.geocities.com/Area51/Omega/9016




[This message has been edited by jon303 (edited 25 December 1999).]
 
440C is difficult to regrind because of the low tempering temps....only around 450F....isnt there a knifemaker in your next of the woods, it can be done in 5-10 minutes.... including a mirror finish if required...

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http://www.mayoknives.com


 
On small blades I like to heat treat before I grind because the tip will lose heat too fast or get too hot when ground down too thin. I just find it easier and when using bare hands, the heat build up is noticeable quite readily. Keep the water bucket close. One of the main problems of heat generation is using a worn belt too long. A fresh belt will cut off more and will produce far less heat. When hollow grinding, it will stay in the grind easier also.
Ray Kirk www.tah-usa.net/raker
 
Hi,
Just to clearify, the blade steel on the Sebenza is BG-42, I'm not sure exactrly how 440c came into the picture
smile.gif
But thanks for the info as usual.

Tom, I will look into finding a maker in my area, thanks for your help,

jon
 
Be particularly careful where the material is thin--at the point and at the edge. Hold the blade in your bare hands so you feel the heat.
 
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