View Full Version : Blade warpage while heating?

Ice Tigre
03-18-2005, 05:17 AM
Hey guys,

I know about tension causing warping durring quench if you don't normalive, but
whats wrong if the steel warpes during heating to normalize? I heated a 3/16"x1-1/4"x~10"
stock removal O1 knife slowly, with my oxy-acyt. torch. The blade curved up towared the heat, I ended up with a "C" shaped piece of steel!

Had to re-heat it and put it in my vice hot to straighten it. After having to straighten 3 times I was able to heat it and do an edge quench to harden it. I was glad that I had it straight- or I was going to end it with a curved bowie :lol

any ideas what could cause it? :confused:


Jamey Saunders
03-18-2005, 07:59 AM
An uneven grind can cause warping. You may want to check your grind carefully to make sure it's the same on both sides.

RJ Martin
03-18-2005, 08:06 AM
Gary: two things:
If you started with precision ground stock, I'd be surprised for you to have warpage.
If you started with hot rolled stock, I wouldn't. Taking exactly equal amounts off both sides of a piece of stock is critical to assure straightness.

As for normalizing with a torch, you might want to look into a dual tip that will apply even heat to both sides of the blade. this way, you can clamp it in a vise, edge down, and play the torch back and forth along the length.

the good news is that you probably saved your blade by getting it straignt before HT.

Don Robinson
03-18-2005, 08:13 AM
Judging by your post, I would assume thatv you were applying heat from one side of the blade. As you said, the steel curls up toward the source of heat. It does the same thing when you heat it with a grinding wheel or belt.

Learn to turn the blade evenly while you apply the torch. If you notice it bowing, turn it over and it'll bow the other direction.

Also, what the other guys said.

Ice Tigre
03-22-2005, 10:33 PM
I'm sure it wasn't uneven grinds- I re-did the grind once when it was straight(real carefully too) and it bent again after that.

Yes turning the blade while heating is probably what got it done the last time- I turned it a fair bit while heating the edge for quench.

RJ; It was precision ground stock that I started with. I will definately see about a split tip-
I didn't know they made such things :)

I'll be posting some pics of my latest work in the "display case" later today if anyone wants to see this thing.

Thanks Again Guys!