Normalizing 52100?

[Silverado6x6]

I'm a newb here, this morning I was tinkering around at work thinking of making me a sturdy hunting knife similar to a Kabar or Bowie and with a very large Timken roller bearing race I cut it in half and proceeded to straighten it out, its now angular(thicker on one side) and yes its now a straight bar about 10" long.

Question is what steps do I take as far as "normalizing", I have never heard that term before, also should I heat it up to quench in oil? I have over 600 gallons of used diesel engine oil plus I can make some brine if needed.

I have never made my own knife before, thanks.

 

[mete]

That's not a beginners steel ! Besides Timken uses carburizing grades which are not suitable for knife making. If you have the bearing number Scott Ickes can tell you what it's made from.If this is your first knife you need to learnsomething about heat treating by reading all the tutorials you can find.

 

[Will52100]

I wouldn't suggest 52100 for a beginner, though it can be done, just takes a bit more work and doesn't like to move under the hammer.

If your going to grind and not forge I'd bring it up to non-magnetic, be very carefull not to over heat! Just to the point where a magnet stops trying to stick to it, actual criticle is about 50 deg. higher if I remember rite. Let it air cool, don't try to hurry it up, let it cool to the touch, then normalize again. Do this 3 times to ensure everything is where it should be. Then grind to shape, drill for the handle, ect. Normalizing is bringing the steel to a "normal state", meaning no stress, or releaving built up stress in the steel from being bent and flexed. I'm sure someone else can probably explain it better.

Some will disagree with my heat treat, but I've found it works for me and my equipment. I tripple quench roughly 24 hours apart then temper at 375 deg. for two hours each time letting cool to room temp between tempers. Test the edge for chiping, if it chips raise the temper 15-20 deg. and temper again.

I use Texico type A quenchant heated to 135-150 deg, which is basicly heavy mineral oil and a slow quench. I use it becuase I know exactly from one blade to the next what it's going to do. For your first there's no reason you can't use a substitute, it's not ideal, but it'll do the job, and there's still a lot of people get excellent results without buying quench oils, I just like the consistancy.

 

[Silverado6x6]

Its a roller bearing race made for the driver axle of an old concrete mixer, it means little to me if it fails, yes I noticed it was very difficult to hammer. I am thinking of welding some 8018 rod to the spine to give it some backbone.

I know that you old timers have heard it every day about someone asking what kind of steel this piece of scrap is and whatnot, I am a fabricator but what that is means I basically cut, and weld structural and mild steel, on some occasions I have to weld hardfacing materials on components used inside concrete batch plant mixing machines, what it is that I have a lot of scrap stuff like this, LARGE industrial ball bearings, what we call "AR" plate that we use for concrete block moldmaking boxes and grader blades we use on loaders and such.

Also since I am the main mechanic at this concrete batch plant I have a large bucket full of broken zip gun bits and the larger concrete demolition bits from the bigger guns, its tough stuff to grind an edge on I can say, I was going to grab a chunk of that stuff for the next knife project. I have no idea what its called though. Thank you for the explanation of normalizing 51200, I was vaguely familiar with it with other metals but after some searching found out that while 51200 is a sought after steel its very finicky about tempering as you say, not a beginners steel obviously.

perfect! just what I want, a challenge for my skills!