Any machine shop use for Grade 10 precision steel,balls?

[Milland]

The first knife on this page is ball bearing canister Damascus. B.U.K. Series Knives by Neilson's Mountain Hollow

I have to wonder how practical those "damascus" BB knives are, given that 52100 is usually pretty brittle at bearing hardness. I'm sure they're drawn down from that, but I'd still worry about breaking a chunk of the edge off in use.

 

[Limy Sami]

like this

View attachment 344463

Yup, and for ''final'' hole sizing, ....I once made some (several dozen IIRC tiny lubricator type pumps - drawn Alu Ni Bronze bodies with 1/8 dia bores <> 1'' deep ------- after reaming the bores were still an nth of an nth tight and felt rough, ....a 1/8 ball bearing pushed through and not only were they crack on size they slid like silk off a baby's bum.

 

[richard newman]

Neat, but don't do this with Oilite bushings. Would sorta' ruin them...

Indexing head for a woodworking shaper. Hardly any rotation at all, and very slow.

 

[Cannonmn]

Here’s a T. Lipton article on using precision balls for measurement. It isn’t 100% clear to me which surface has the balls glued to it, I’m guessing the surface plate. But now I’ll,have to keep an eye out for a set of precision balls of all different sizes like he has. Fowler’s 52 piece set, grade 24, is $80. Or more depending on who is selling them, there are 52 balls in it ranging from 1/8” to 1”.

Shop Operations: Get your bearings | Cutting Tool Engineering

 

[52 Ford]

I have to wonder how practical those "damascus" BB knives are, given that 52100 is usually pretty brittle at bearing hardness. I'm sure they're drawn down from that, but I'd still worry about breaking a chunk of the edge off in use.

I have to wonder how practical those "damascus" BB knives are, given that 52100 is usually pretty brittle at bearing hardness. I'm sure they're drawn down from that, but I'd still worry about breaking a chunk of the edge off in use.

I haven't tried forging it (I want to, now), but I THINK if you draw back the hardness, it'd perform well. From what little I've read about it, it's just trickier to heat treat than more common knife steels. They want it to soak at 1500 degrees for half an hour, oil quench BUT only to 150 degrees, then immediately temper it at at least 400 degrees. Plus the usual stress relieving heat cycles.

 

[Cannonmn]

I’d like to hear from anyone who actually uses the Tom Lipton precision ball measuring method. I read his article. Shop Operations: Get your bearings | Cutting Tool Engineering A few times and he doesn’t define D1 and D2 except that we know they are ball diameters. It seems to me it’d make a difference whether D1 represents the diameter of the center ball, from which the H height is measured, or the other presumably smaller one(s). Does anyone have a reference that gives a little more detailed explanation of this method? Regarding his suggestion to glue the three balls to the surface plate (or are they glued to the metal plate over the balls?) I’d get three o-rings just large enough to clear the bottom of the ball, put one around the bottom of each ball, which would prevent the balls from rolling.

 

[Cannonmn]

This article clears up D1, D2. The three balls diameter is D1, the one top ball is D2. Temperature is addressed.

Access to this page has been denied.

 

[dian]

I have to wonder how practical those "damascus" BB knives are, given that 52100 is usually pretty brittle at bearing hardness. I'm sure they're drawn down from that, but I'd still worry about breaking a chunk of the edge off in use.

actually 5200 is not so bad. partially austenized at 1500° and tempered 2x at 400° you should get 61 hrc and 28 ft-lbs if you use a quality (vim-var) alloy. toughness wise this is in the lower range of L6 that is much softer. the trade off is much better than with A2 or even some dedicated (expensive) knife steels. as always its all in the heat treat, e.g. starting with a "det" structure apparently provides best results (→ fine carbides).