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View Full Version : Looking for a steel ~200000 psi for an Olympic bar



Sandarpan Mukherjee
11-15-2014, 11:15 AM
Looking for a steel that can have ~200000 psi Tensile strength, 180000 psi yield strength for a 28 mm diameter rod. Application is an Olympic bar 7 feet in length. The bar will be knurled and machined (grooves cut at the ends). Also the bar must not snap on exceeding YS. It should flex and then bend rather than break.

Thanks

Forrest Addy
11-15-2014, 01:01 PM
On the OP's post on PM the requirement was 165,000 PSI tensile and yield. Now it's 200.000 and 180.000 PSi Which is it?

For the record, guys, he wants to make an initial batch of Olympic class weight lifting bars he can resell in his business. The kind I need both hands to lift when its loaded.

We're talking Rc 45 - 50 alloy steel 1 1/8" dia. Knurls, pivoting weight sleeves with bushings, weight retention collars, lots of missing detail and he wants to pay not much. The OP is defintitely not a detail guy. He offers no website link, no specs, no nothing. We're supposed to guess or educate him..

He's getting a hard time from the PM guys for omiitting detail. Apparently he didn't like what he was hearing so he started a new post for material only on PM:

http://www.practicalmachinist.com/vb/general/selection-steel-round-application-weightlifting-equipment-294141/

Note to Sandarpan. We really would like to help but this is a highly technical board and we need specific information on which to base a reccommendation. Do you have a drawing or a link to a site we could work to. We're not hassingly you. You want to have made to order an item of athletic equipment that may cause injury or death if it fails. catstrophically. There's no escaping the need to consider the technical and legal aspects of your requirements. I say legal because you have to consider tort exposure but patents,etcc. Your product has have at least a few features distinguishing it from your competition.

As I see it you need a bar, collars, bearings sleeves and a tool-less weight retention device of some kind. The bar itself will weigh 28# there abouts and the material will be a couple bucks a pound. Add machining, (grooves, knurls, heat treatment, prep and plating and I could see it costing right around a hundred bucks each in 100 lot quantities. The other items may double that and that's your cost. Add freight, shipping, profit etc....

You need to define your returements and draw them up in a form a manufacturing shop can draw a quote for. Right now you're wasting your own time and frustrationng the people trying to help you.

So we need either a drawing or an example you can point to. Something from which we can take dimensions and spec materials. Once we get that maybe somone can point you in the right direction.

Rich Carlstedt
11-15-2014, 04:31 PM
Shaking my head........
A weight lifting bar that will reach 180,000 pounds stress ? ( .954 square inch area )
So the lifter has to lift 90 Tons before failure ?
I think he wants a tube ! not a bar
Take your pick
4340,
8650,
52100
Best bet for a tube is 4340
I believe the motorcycle guys use it

Rich
not being sarcastic here---just wondering ?
Think the Op needs a Structural Engineer as HT and wall gets pretty critical

Ohio Mike
11-15-2014, 04:53 PM
Google found this post from the OP on the garage-gyms web site:

"On a side note, I’ve always wondered what kind of steel barbells are made of. Especially the 200000 psi Tensile strength barbells. It seems steel becomes brittle at high strengths. At least the steels I looked up do. What steel could have such high strength and yet flex enough to be useful as a barbell?"

mike4
11-15-2014, 05:36 PM
Surely a steel supplier could use the numbers given to list steel alloys with the OP's broad specification.

The other details are not really relevant , eg diameter and length are given , the knurling and other details would not really matter .

I cannot see why all details must be given , all he wants to know is what steel alloy would suit this application and here there is no tolerances that most of us are used to working to , its only a rod to support weights and he obviously doe not want some brittle material which will fail either during the first lift or at any time subsequently .

The carry on about drawings is amazing as I and others often work to similar requests .

Not hard to work from a rough description , eg , 3/8" stainless rod , bored to allow 1/4 20 bolt to pass through , overall length 1 1/16 " and please make 10 of them.

What they are used for and where they go is not my problem as the customer is not obliged to tell me .

I just make the part and there my responsibility ends as the end use of any product is the customers responsibility , not anything that I can be held responsible for as it clearly states on the invoice .

The others who are only looking for someone to blame if something fails need to get their heads out of the cavity that they are currently in and find some common sense.

Michael

RussZHC
11-15-2014, 06:19 PM
http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CEkQFjAD&url=http%3A%2F%2Fwww.iwf.net%2Fdoc%2Ftechnical.pdf&ei=oNtnVNHlGdCsyASwwIGgAg&usg=AFQjCNED0ZQV-U7jkh_fOm8GkUx_jkdOcQ&bvm=bv.79142246,d.aWw

the above is link to technical pdf for federation supervising "Olympic" lifting, page five and top of six cover the bar as to weight, colour markings etc., drawing for bar (men and women are different) dimensional last page (page 31 this version)

Read all the threads from PM, not sure that its not question asked and answered at this point.
Conceding to far greater in-depth knowledge than mine plus just general pricing of materials, I just don't see how the OP of the thread in PM can get what he wants for the price he asks about which is considerably lower than the one he is implying he can already get it for...I don't see any proof that what he says are made in USA bars are in fact made in USA (that seems to be some good portion of the thread discussion) esp as the "Made in USA" seems to have sort of a floating precision as to "made"...could it be enough for those suppliers to have the parts made overseas and then assembling in the US being enough for it to become "Made in USA"?
Edit: in interest of fairness, I took a quick look at the Rogue website (no connection, was mentioned several times in the PM thread) and I can see how their bars can be actually made in USA but would add that their popular "Ohio" bar lists at $329 plus change Canadian and their Olympic WL lists for $715 plus change Canadian and their Burgener Bearing bar sells for $761 plus change Canadian (prices for bright zinc, chrome and polished chrome more)
to see some of the process, http://www.roguecanada.ca/rogue-olympic-wl-bar#customer-reviews. I could not see anywhere, if as most Olympic equipment makers, they are actually making equipment that meets international standards for use in Olympic competitions.

If you were to see, touch and use an Olympic bar from one of the three world known suppliers in the PM thread, you might be surprised at the remarkable differences in quality and some of those differences (bearings for one) are pretty important to those athletes using them. More so in competition. If the bars are not going to be used in competition and just need to function and fit the weight center size, then the costs get lowered a lot but you can only go so cheap before those bearings are not going to do what they need to do or the bar have somewhat of a useful life span. The part of the university where I am most often, of the 6 or 7 "Olympic" bars, there is maybe, maybe one not bent to some noticeable degree (here anyway, competition bars will never be used for training purposes).
Not sure where the drop test numbers came from in the OP thread, 5 feet as a height is just not realistic, too low, weight is little on the low side as well...many lift day to day at 1.2x to 1.8x their body mass for some lifts so competition will be more.

http://vikingweightlifting.com/eleiko-weightlifting-bars-and-discs/, be sitting when you see the prices

http://www.werksanusa.com/COMPETITION/products/10/

http://www.ivankobarbell.com/products/obs20kg/

based on what I have seen, I suspect there are only a very few making this type of bar at the highest level and making them for more than one supplier/seller, so as the posters seems to want to do, break into that market, going to be tough. And, if some of the makers are true to their word, one can see why the cost is so much...to me anyway there is a big difference if you test and scrap or test and straighten and use for a lesser quality bar.

KiddZimaHater
11-16-2014, 12:06 AM
I want to see the guy that's going to bench press 90 Tons. (180000 Lbs.)

Sandarpan Mukherjee
11-16-2014, 01:09 AM
Firstly thanks for all the replies. There are a few clarifications to be made from my end. 1. I am not the poster who had posted about the 165000 psi bar on PM 2. I am not looking to go into business with my barbell. I will make only 1 barbell or at most 2 as a backup. This is for my personal use only. I will not make it myself but get it done from a shop who has never made such a thing. So it'll be kind of a hit-or-miss thing.

I have "designed" a barbell based on existing designs. I figured that if all the high end bars cost ~ $800-900, making one should cost me around $600-700, taking into account that I'm not producing in bulk and I don't have to add the profit, overheads and brand cost to my product. One increases the cost while the other takes it down. The other thing is that I live in India. Labour is fairly cheap here. Actually make that very cheap. Don't get me wrong though. I would always prefer to buy a barbell rather than make it. But all we get here are the ****ty Chinese one, that bend too soon, the chrome flakes off and what not and importing a Werksan or Uesaka inflates the cost to nearly $2000.

I could provide drawings for what I'm making but I doubt how helpful they will be. The sleeve material doesn't matter at this point. I'm trying to zero in on the shaft material. I would like it to be available in the Quenched and Tempered condition with the above specs. Being a non-Metallurgist or a Mechanical engineer I am not sure how each material will behave as a bar. The bar will be machined to some degree (knurled and grooved at the ends). I want to bar to be the same quality as the top end bars but at least I'm not gonna have to worry about warranty. :)