Bending barbells?

[Robert NL]

I am not sure about composites. I have seen far too many delaminations. That is an extremely interesting thought, however. Powder metals is a fascinating world I wish I knew more about. Right now my favorite material of choice for a bar would be 17-4 PH H900. We have extensive experience with the alloy. It is almost indestructible. I have even made springs from it. We make sway bars, hubs, pins, bolts, all our stressed parts from it. It is unbelievably strong and really corrosion resistant. I love the alloy. We have destructively tested parts by bending them (permanently) 90 degrees and they still don't break.

The heart attack threw a wrench in things. I am back to lifting about 1/2 of pre MI. It really feels nice to get back under the bar. That combined with the fact we are really tied up right now at work (thankfully) means I will finish it by Christmas. I know Rip may groan at that but it is the best I can do at the moment if I am going to be realistic.

Yeah laminates can be a disaster I know. I was thinking of a high hardness (~58hrc) pm steel inner shaft with a milder much more deductible outer layer forced around it. The whole thing would be produced oversized and after an aging cycle it would be precision machined to be absolutely straight. The plate shafts would turn on two needle bearings supporting the shaft on both sides. Of course the whole thing would be blackened like they blacken a gun. Yeah dream on...

17-4 PH H900 that’s stainless right? Sounds interesting. Shouldn’t you save these revelations for the article though.. That test is impressive. I make knifes as a hobby and destruction test them. The best I got was an 80degrees bend in O1@56HRC but that is mild steel compared to the stuff you’re working with. What hardness was that piece?

Good to hear you are on the way back. Christmas is pretty soon.

[David Kirkham]

Yeah laminates can be a disaster I know. I was thinking of a high hardness (~58hrc) pm steel inner shaft with a milder much more deductible outer layer forced around it. The whole thing would be produced oversized and after an aging cycle it would be precision machined to be absolutely straight. The plate shafts would turn on two needle bearings supporting the shaft on both sides. Of course the whole thing would be blackened like they blacken a gun. Yeah dream on...

17-4 PH H900 that’s stainless right? Sounds interesting. Shouldn’t you save these revelations for the article though.. That test is impressive. I make knifes as a hobby and destruction test them. The best I got was an 80degrees bend in O1@56HRC but that is mild steel compared to the stuff you’re working with. What hardness was that piece?

Good to hear you are on the way back. Christmas is pretty soon.

Thank you for your kind words.

That would be an extremely interesting bar. PM is an amazing world.

Yes, 17-4 is a precipitation hardened stainless alloy. H900 refers to the temperature of the oven (and in turn the strength of the material). H900 ends up about 210-220,000 psi UTS. Yield approaches 200,000 psi! Fatigue is outstanding (we make springs out of it) and corrosion resistance is great. H900 hardens up to about Rockwell C 44. It really is a magical material. I have never seen it fail--even under extreme abuse. (Unless the part suffers from an incredibly stupid design). Even then it will hold up far longer than you can believe.

[Robert NL]

Yes, 17-4 is a precipitation hardened stainless alloy. H900 refers to the temperature of the oven (and in turn the strength of the material). H900 ends up about 210-220,000 psi UTS. Yield approaches 200,000 psi!

Thats amazing. I might just expirement with that in the future. I can think of a few aplication already.

Fatigue is outstanding (we make springs out of it) and corrosion resistance is great. H900 hardens up to about Rockwell C 44.

Is that martensite or bainite? Given that you use it as a spring and all.

@ Rip
Sorry for metal-freak talk on your board. Any plans on incorporating Davids wisdom in a new Rip-bar project? If so, put me down for one.

[Mark Rippetoe]

Once again, we are not in the equipment business.

[Robert NL]

Once again, we are not in the equipment business.

Got that. I was refering to an B&R type project.

You affiliated with a bar before and now an article about bars is in the make. Didn't seem like that big a stretch.

[Mark Rippetoe]

If you guys make products, I'd be happy to promote them. I think there is a big market for David's squat handles.

[Trekker]

I believe Chapman Welding used to make a barbell from 17-4 in 29mm diameter.

The last to sell them was Mavrik Barbell.

[Mark Rippetoe]

That was a helluva bar. Legendary. Their website could use some work.

[Bryan Dobson]

I had a nightmare last night. in it I took a rogue bar to a camp gym on the north slope of Alaska and some asshole bent it.. I had to train for two weeks with a bent bar...... I haven't been to the slope in 5 years. I blame this thread.

[vkp78]

Wanted to say this for a long time. Sometimes I dont understand what the heck is going on, like the exchange between David and Robert, but when you see the expertise and enthusiasm of people in this forum, I just feel like I got invited to sit at the grownups table. And I am willing to shut up and listen.....for the most part anyway.
Rip,some of the guys you have in this forum are awesome and thanks!