Technical Sourcing four bar stainless tubing

Hey all,
What are your thoughts on stainless tubing for triangulated four bar suspensions?
I have purchased these stainless rod ends from Speedway:

These have 5/8-18 threaded ends.
Would you recommend machined tapped and welded ends in larger diameter tubing or maybe heavier wall tube that could simply be tapped? The I.D. of said tube would need to be about 1/2".
I'm leaning towards the heavier wall tube and simply tapping, but where would one find such tubing?
Thanks,
Jeff

 

GOOGLE?

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=stainless+steel+tubing

 

Yes Google, not always the magical thing we hope it to be. All I seem to find is major mills and suppliers, not the walk in type of businesses. Just hoping someone could save me a night of 50 page deep Google searching. Heavier than normal tube seems to be kind of an odd duck.

 

Just trying to help, man.

 

https://www.mcmaster.com/#metals/=150y81u

They only show maximum lengths at 4' though....

 

With no idea where you live it's difficult to help. If you live way out in some back water place that is miles from anywhere, then you might have a problem.

Otherwise I can't see the issue, or the need for your question.
Most major cities have a good industrial metal supply and all you need to do is call and ask for what you want.

As for the material size, look at what the people who make the 4 bars are using, usually mild steel of course and then ask for the same size but in stainless.
Why make it difficult ?

 

Tell us you are going to do the tapping on a lathe.
And those that have done it without one, please, no cards and letters.

 

Thanks Steve,
Thought McMaster was a bits and pieces supplier. I checked out the link you provided. They do have a size that would work but the price is prohibitive. I appreciate the effort.
Jeff

 

Yes sir, lathe tapping. At the very least started in the lathe.

 

Was I rude in a previous post or something? I don't see how I've made anything difficult. I reread my original post and they all seem to be reasonable questions. Did I mention that I had already done Google. No. Who doesn't know and use Google? The mere suggestion on a forum to use google is almost rude in itself.
What is a forum for? Is it not the sharing of ideas, knowledge and information?
I don't know, maybe it's easy to forget that everyone has to start somewhere. This is my 4th old car, but my first ground up, so EVERYTHING is new to me. Every step is new territory. Every step is hours and hours of research. A forum such as this is an invaluable resource for guys like me, the vast majority of members being very willing to help.

As for me, I'm going to live by the old adage "there are no stupid questions". And I tell you what, if I can answer a guys question and share information to make his life a little easier I will. If I have nothing to offer, I will assume he has done his Google search, I will assume he has done his forum search and keep my mouth shut and let those who DO wish to help, do so.

 

www.onlinemetals.com
I buy small cuts there a lot, fast shipping

 

I wasn't rude. You could have easily found out what size tubing is used in 4 bar systems and then searched for local steel or even stainless steel suppliers.
I answered your question in a reasonable enough fashion.
I didn't suggest Google.
Good luck in your search as I said, most major cities have industrial materials that will be able to get you what you need once you know what it is.

 

Thanks bardahl1,
Looks like they DO have a 1"OD 1/2"ID option there. 1/4" wall stainless should be strong enough you'd think.

 

It's actually not as easy as you might think, if they do give you an O.D. they certainly don't give you a wall thickness and I'm not so sure dimensionally identical mild steel and stainless steel are equal in strength.
And yes, you were rude. Take 2 sentences out of your first response and it has a completely different helpful tone.
Ask yourself if "Otherwise I can't see the issue, or the need for your question." or "Why make it difficult ?" were really necessary.

 

your weak link is any load bearing suspension part from speedway. there is probably much better out there, I'd look at Alston's Chassis Works

my guess is .250 wall is thicker than usual. I am always suspect of shear load on any stainless suspension part or bolt. 4130 / grade 8 is optimum. Stainless is very hard and brittle

 

Excellent
Don't know your experience so these tips might be helpful.
If you have a lathe available, why would you not finish it in the lathe?
Make sure the I.D. is correct for the intended thread and ALWAYS chamfer the tube I.D. before tapping. And no, even people that should know better fail to do this many times. It's possible to roll the first thread in if a dull chamfer tool is used after tapping. A good tapping fluid is Rapid Tap from industrial suppliers, or the big box stores have pipe cutting fluid such as Oatey brand.
Happy tapping!

 

There will be a lot of fun in drilling/tapping Stainless..

 

I don't have a collet for the tailstock so tap would start to spin in the chuck but would have a good straight start. Got the Rapid Tap. I always chamfer out to the thread diameter. Have not tapped stainless though, slow and steady, plenty of chip breaking is my guess. I wil lprobably google it first...
Thanks DDDenny

 

Decided to fab my motor mounts out of stainless, learned a lot in the process!

 

Me, I'd use DOM tubing and chrome it - a lot easier to work with, has great strength and is available in a variety of diameters and wall thicknesses.

 

If it were me, I think I'd go with weld-in plug ends that are already tapped and use thinner-wall tubing. The bars would be at least partially unsprung weight, and the less weight the better. And you can get stainless stick rod (works best with a DC arc welder) so TIG isn't absolutely needed. The welds will polish up very nicely...

 

Ok well here you go.
Most people will not use stainless tubing as has been said by a couple of the other posters.
Issues with threading and other reasons.

DOM (drawn over mandrel) seamless steel tubing which is chrome plated (after cutting to length and threading ) is the best way to go.

The size you need is 7/8" OD with .156 wall thickness.
That allows you to thread the ends for the 5/8-18 rod ends.
Hope that helps.

 

Very helpful.
Hey I did more searching and did find a stainless four link kit with specs - It uses 1"x.156 tube bars. FWIW
Thank you Blue One

 

Stainless tube is always expensive, and particularly so when you need something with a heavy wall relative to the tube OD. A few different online sources price 1" OD x 1/4" wall 304 SS tube at $21 to $30 per foot in cut lengths.

If I was making a one off 4 link like you want, I'd use 1" solid round stock rather than tubing. The tubing above weighs 2 lb/ft while the solid weighs 2.7 lb/ft so the weight difference of the finished parts would be negligible. I'd use either type 303 or type 416 stainless. Both are free machining grades which means they will drill and tap about as easily as mild steel. Either one should be in stock at large steel suppliers like Ryerson or Jorgensen or any number of others around the country. Both come standard in 12 ft lengths and you should be able to buy a 12 ft length of either one for $100 or less if you pick it up at the warehouse rather than shipping or having it delivered.

If you use tubing you will have to bore to the proper size for tapping. Trying to run a 37/64 drill into a 1/2" hole in 304 SS will give you a poor finish, a wrecked drill, an oversize hole, or all 3. With 303 or 416 solid you can drill to size in the lathe in one shot and have a good, on-size hole for tapping.

And, to clear up one misconception, common grades of stainless are neither hard nor brittle. The chrome and nickel content makes the non free machining grades difficult to cut and tough on cutting tool life.

 

Useful info, thanks for sharing.

 

Look up tap tube for your search. I get the DOM steel tubing from a local circle track place. Dimensions are .812 o.d. and .562 i.d. Stainless will be pricey.

 

No 400 series if you are planning on welding, the welds get hard and crack. 304 Stainless has about the same mechanical properties as 4140 but less machineability and fatigue resistance.
Stainless can be polished cheaper than DOM can be chromed, but you are asking for trouble tapping it, galling the threads so you can't get your rod ends adjusted, and the fatigue life will bite you in the ass.
I want my axles to stay put, so I would never consider stainless suspension componants

 

I buy from Speedy Metals, local for me but they ship anywhere and cut to length.
http://www.speedymetals.com/default.aspx?

 

for tapping any stainless .........a gun tap is a must ..... I still have my original 5/8" and 3/4" unf gun taps that I bought over 40 years ago , they still perform as new and I have made hundreds of 4 bars......I only use 316L stainless tubing ....the L is the low carbon......oh yeah , only use Trefolex as the cutting compound cheers

 

Tube Service (800) 669-2169
All over the west
I get all my tubing needs from Tube Service
I haven't found a better price in my area and delivery is cheap.
Cost me $20 no matter how many lbs I buy. I can't drive there that cheap.
I also agree on using DOM.


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