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So I had taken apart a huge ball bearing awhile back that had a bunch of 1.030” bearings... 

 

I've had these things on my workbench for a while now and wondered whether they’d make a knife or not, so I spark tested on, it sparked like majorly high carbon steel. I forged one flat, did a quick normalization, and then quenched it in oil. I tried bending it, and it broke like glass. Whatever the steel is, it’s pretty tough, and gets hard as glass. 

 

Anyway, today I set out to see what I could come up with. I didn’t really have a plan in my head, and just kinda went with it until I started to see a tiny skinner/neck knife-ish profile shaping up. 

The first pic (why does the editor screw up the order of the pics) is 80 grit off the grinder (I had to come in for a bit and rehydrate)

The second pic is 90% as-forged. I had straightened the spine and touched up a bit on the edge on the grinder.

Finally, the last pic is post heat treat at a worn out 120 grit belt finish. 

It has a 2-1/8” blade that’s ~1-5/16” wide at its widest. It’s .20” thick at the tiny little ricasso, and distally tapers to .125” where the bevels meet the upper edge. 

Let me know what you guys think... and I’d love to see what you guys could come up with using similar materials 

45D39554-801A-4DF8-921D-80264D69FCD2.jpeg

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The volume of a 1 inch sphere is .524".  Is this a volume challenge, or a control of mass challenge?  A 1 X 2 X .25 piece of stock is just a bit less mass, but working from a sphere is a challenge all by it's self.  Can I use power tools, or is this a hand hammer only thing.

So many questions!

Geoff

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Use whatever tools you like! I only used a hand hammer, but that’s only because that’s all I have for now... 

I think round stock could work too, just would have to use less than an inch to have the same volume

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3 hours ago, Eric Morgan said:

(why does the editor screw up the order of the pics)

The editor arranges the pics in the order they are uploaded, unless you use the "add to post" button hat looks like a + sign in the photo tile. Using the + button adds the pic wherever your cursor is.

2 hours ago, Geoff Keyes said:

The volume of a 1 inch sphere is .524".

I get .572 cu. in. So if you had the 2x.25 flat bar, a 1-1/8" strip is roughly equivalent. I do like the idea of a 1" sphere though. I'll see if I have any out in the shop. I know the wife has a bunch of steel balls for her artwork. Sometimes she buys the chrome ones, other times the HC steel. She might have the 1" ones lying in a bag, inside a box, stuffed into a cabinet.

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Ball bearings are usually 52100, which is good stuff.  I don't have any 1", but I have a couple of 3.5" I plan to use as mushroom stakes.  

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Wow, I’d hate to think about hand hammering a 3.5” ball bearing :lol:

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I've tried it with a bearing I got from a QC shop that rejected some that were to be used as tank turret ball bearings.  Even with a striker it was a nightmare.  Did this a while ago, so likely not in good control of heat, but still...

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If it helps any, Jason Knight told me to thermal-cycle them a few times before attempting to forge them.  

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I’ll have to try that next time around... they really don’t like moving under a hand hammer at first:lol:

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I read, several years ago, that the bearings need to be annealed, or at least normalized before forging.  This article described a smith just heating a bearing and when he hit it with a hammer it exploded.  Not good.

Wayne

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I didn’t anneal or normalize the two I forged, but I did make sure to let em soak for a few minutes to make sure they were up to temp all the way through... could’ve helped avoid that scenario maybe

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Maybe I still had internal issues in the steel, after all... I was looking at the blade with a coworker last night, and noticed a hairline crack in the spine :unsure:

So, this morning when I got home from work I used that flaw, and my not particularly caring much for the blade to tang transition, to break the blade to see the grain structure. 

Ive attached a pic, lemme know what you guys think. I think it’s not too bad, the grain seems reasonably fine to my inexperienced eye at least

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16392200-FD19-4205-9337-9D9F639FC280.jpeg

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Yep, looks pretty decent.  Too bad about the crack, though.

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Yeah... it happens though I guess. I’ll be more careful next time with this material, cause i don’t know if it was maybe forging too cold that did it, the quench, taking too long to get it into the temper, or existing stresses... 

But I guess that’s true of most reclaimed material failures in knifemaking...

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I don't have any 1" bearings, so I sliced 3/4" of O1 round off and forged that out.  My camera died early on, so I only got a couple of pics, but as soon as the battery charges, I'll have a couple more

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I cut this with the chop saw, just to give me a starting place.

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I heat with the powerhammer

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A pass with the press.  It got a lot easier from here.  More later

 

Geoff

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Last pic for now.  I got nearly 7 inches pulled out of that little piece, just over 4 inches of blade back to where I will cut the shoulders.  Not too bad.

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A bit of NS and some stag and I'll have a little B&T.

 

Geoff

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I only have a 7/8 in ball bearing......would that work for this challenge? 

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Posted (edited)

I get some time this weekend I may try something like that.  Got a free sample of 1085 from Pop's supply at a recent hammer in.  It's about 2"x3/4" or 2"x5/8" round if I remember rite.  I know it's not quite in the 1" criteria, but it should be interesting since I normally work a lot larger stock.

My experience with 52100 is to thermal cycle it before, durning, and after forging.  Knock on wood, I've only had a couple to develop cracks over the years even with lower temp forging cycles.  It really responds well to multiple normalizing cycles.

Edited by will52100

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I gave it a go but I used 1 cubic inch by mistake... it was 3/4" square by 1.8". maybe tomorrow ill try a 3/4" cube. It rained real hard here today and my japanese style hole in the ground forge is underwater...

 

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