ok, either im missing something or...

stoopid server, deleted my post!

that and i ive gotten an email from bladeforums 3 times saying Beknives has responded to my topic, and he hasnt in 3 days :)

anyhow. my first post was much longer than this one, but im not typing it again:

heres the lowdown...

read on Mad Dog's website tour this:

A 400 grit belt polished the flats to a final sheen. Even in this stage, the blade is water cooled after EVERY stroke on the belt. This keeps every bit of the steel in its annealed stage right up to heat treat. There are many makers out there who will overheat the blade in the preliminary processes by outsourcing blank cutting to laser cutters, by cutting blanks with a cutting wheel, or by speed grinding by pushing the blade with all their might onto the belt grinder. You can tell because after these processes, various colored oxides have appeared on the blade signifying changes in steel properties due to high temperatures. This may not be detrimental on the spine but if you have properties changes in the cutting edge prior to heat treat, there will be no way of scientifically controlling how the steel changes during the hardening process. It is amazing the number of makers out there who have not the slightest idea about steel and the effects of heat on its properties.

anyhow, this is all pre hardening.

i thought that you couldnt get the steel too hot during the grind, and as long as you dont quench it during grinding it wouldnt change the properties of the steel, it would remain anealed.

i suppose you could get it hot enough to burn out some of the carbon? but that would be REALLY hot.

heck, if you normalize after grinding, doesnt that bring everything back to start anyhow?

help me out if im just confused. or maybe its just propaganda kinda advertising?

either way, thanks

this one better go through :)
 
From what I've found, yes you can get the steel hot enough that it will harden in spots. Only enough that its a pain to cut or drill though, its not on the same level as after you HT. And thats a big part of why you normalize before you heat treat. If you didn't there could be stress build up from the uneven hardening of the steel.
But I think as long as your holding it in your bare hand you haven't got it hot enough to actually damage anything.

Now after heat treat its a whole different story, you can easily get it too hot then, partly because your grinding on a much thinner peice, and partly because the belt doesn't cut as quickly. The only damage you really do then is ruin the temper. Thats when you get the color changes, blue and your screwed, brown is really bad. Really, you don't want any color darker than what the blade comes out after tempering, its best if you don't get any color change at all.I suppose at this stage it would be easier to damage the steel by overheating it, but again your talking about temperatures so high you'd have to be holding it with vice grips.
It really isn't all that big of a deal, take your time, try not to burn yourself to bad and it should turn out alright.
 
you've had O1 harden on you while grinding?

i generally profile my blades pretty close while wearing gloves. after that i grind barehanded. i wonder if im getting them too hot? they dont change colors so i bet im ok. especially since i normalize before hardening.

hmmmm...
 
Think about it this way.... when you heat treat you get your steel, up to a glowing orange, and it has no ill effect on it. If it burned all the carbon out or did anything horrible, we obviously wouldn't be doing that would we?

Also, O1 is oil hardening it needs a fairly fast quench in order to harden. I have never noticed any significant work hardening with it, but then I don't ever wear gloves. (you'll quit when one gets sucked between the belt and workrest:eek: ) Air hardening steels, only require an air quench, so getting one good and hot on the grinder, or bandsaw, or mill and letting it air cool can in effect harden it.

Also remember that there are at least a million and one ways to screw up a knife. I don't plan on worrying about the miniscule effects unevenly hardening before normalizing and hardening will have until I can consistently making a knife without making one of the other million mistakes :D

Just take your time. Don't let it get hot enough to set your gloves or hands on fire, and in the even that it does get some oxidation or scaling on it, make sure you grind it back down to smooth steel. (something you would do in the finishing process anyway)
 
when you heat treat you get your steel, up to a glowing orange, and it has no ill effect on it. If it burned all the carbon out or did anything horrible, we obviously wouldn't be doing that would we?

ya see, thats what i thought.

ok then :)
 
A LOT depends on which type of steel you are using.

The more common stainless hicarbon steels do NOT work harden.

Certain others do........I made a bunch of Vasco Wear blades a while back and ground them like I always ground 440C- The stuff got harder than anything I had EVER seen BEFORE I sent if off to heat treat. What a pain in the butt. You need to do some research on each type of steel and the effects of low temp heating on the material.
 
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