Technical Tap tube?

Seems I remember years ago seeing tubing called "tap tube" where the o.d. was adequate for hairpins and the I.d. was already the right size for threading for tie rod ends. Anyone steer me towards some? Thanks

 

Try speedway

 

Most larger cities' steel houses will have D.O.M. tubing, that meens drawn over mandrel.
Depending on size required some inside diameters may need slightly enlarged in a lathe.
Warning, some math may be required.



This thread may or may not be of help.
http://www.jalopyjournal.com/forum/threads/11-16-taps-where-to-buy.73347/

 

Here is another helpful site.
Call out is for 5/8-18 thread, common for rod ends.

http://secure.chassisshop.com/partdetail/10-78-156/

Note comments under description.

 

gives you the ID for chromemoly tubing

 

Yep we used 1" by .21 for 4 links using a 3/4 heim. It had to be reamed slightly for the tap.

I don't doubt that at some time someone marketed a tube that was already sized for a tap but they were smarter than the average Joe and knew that they could sell something that anyone could buy for themselves at a slightly elevated price.

 

IIRC -7/8 od .156 wall DOM for 5/8-18 & 3/4 od .156 wall DOM for 1/2-20 , plenty of charts online ..
dave

 

Pretty easy to figure if you own a machinists hand book or a tap/drill size chart.

Basically you take the OD of the tubing minus the wall thickness times 2. OD-(wall thickness X2) Most builders will tell you that if you intend to stress the part very much that you are better off to use tubing with a drilled and tapped insert welded in.

 

I don't understand why a welded insert would be any stronger than tapping the tubing ??
dave

 

Lefthander Chassis has it.

 

Lots of things I don't understand I just know that they work.

If you look at manufactured ladder bars or 4 links you will find that they make two grades, the welded inserts are rated at higher HP then the tapped tubes. If I had to fathom a guess I would think that it had to do with the manufacture process and that drawn tubing does not have as tight a grain as cold rolled or forged steel.

 

Here you go.
http://secure.chassisshop.com/categories/5625/

 

Maybe a "rolled "thread vs. a cut thread ??
dave

 

Correct
External thread rolling is considerably stronger (under most circumstances) than die or single point threadng.

Good info. here.
https://en.m.wikipedia.org/wiki/Threading_(manufacturing)#Thread_forming_and_rolling

 

When P&J got their 4 bars established, the tubing they used was thinner wall than would have tapped 5/8". Ergo, the welded-in bung.
Then Ed Moss began marketing the offshore Stainless 4 bars. More thinwall, with bungs. Measure some.

 

Competition engineering sells them both ways with or without inserts. The insert models are rated at higher HP and bot use the same tubing.

 

Stock Car Steel has DOM tubing and 4130 - in all kinds of sizes. I just had to order some 3/8 x 3/8 .035 wall 4130 - one of the few places that has that small.