Stupid Question???? Re: Tubing size.

[SteveM]

I'm checking with my local suppliers for roll cage tubing, and an interesting question has come up.  I'm looking for 1-5/8 x 0.134" tubing.  Several people have 1-5/8" x 0.120" wall, but I haven't found 1-5/8 x 0.134" wall yet.   

One of the local suppliers has offered tubing which is 1.66" on the OD, with a nominal 0.139" wall.  Looking at the charts, this looks like it is actually Schedule 40 pipe material.   The size matches pretty close to what 1-1/4" Schedule 40 should be (1.38 ID x 0.140" wall). 

I can't tell from the rulebook whether this is allowed or not.  Dimensionally, it fits the minimum OD and wall thickness requirements.  Advice would be appreciated before I buy any tubing.

Steve. 

[Tman]

Get the specs from the supplier, tensile strength etc. Lots of tubing is sold in "pipe" sizes but in reality is the same mild steel. After you get the specs, talk to the tech committee person for your class.

[SteveM]

Good idea - I learned something new (mechanical tubing sold in "pipe" sizes).  The supplier did tell me that it was mild steel tubing, it was just the size that threw me off.  I'll try to find out more tomorrow.

Steve.

[Peter Jack]

There are actually a couple of sizes of steel tubing made with pipe dimensions. They make it in those sizes for use in handrails. In the past handrails were made with pipe. I think the main reason was so that the handrail fabricators could continue to use their pipe benders. I've usually got some in stock to match up to existing railings.

I'd be very careful as I'm not sure how well the quality of the product is controlled.

Pete

[SteveM]

I just looked on their website (Ryerson) for the specs.  You guys were right about tubing in pipe sizes.  It is ASTM A500 Grade C (62,000 tensile strength), which is produced in the same size as Schedule 40 pipe.  It's nice to learn something new.

SteveM.

[Tman]

I learned the same from my pal and Mentor randy at R&D Cassis a few years back. Just passing the info along.

BTW, the .166 stuff is common for cattle gates and pens! Whoda thunk?!

[Rick Byrnes]

Steve
It's ok to use 1 5/8" .120"wall tube.  Particularly if it is DOM.
SCTA is not going to measure thickness, or drill to see what you used.
But, it wouldn't hurt to have receipt in your build book. 
With my new build I have kept a looseleaf binder where my SCTA/BNI Log book is kept, with specific information just like that or receipts for heat treating (normalizing) 4130 parts after fabricating.  While integrity is assumed until we prove otherwise, it helps sometimes to have important things handy. (nowdays my memory sometimes needs a kick start...and those things help when I'm asked for specifics)

[SteveM]

Rick:
   I have already started my 3 ring binder of receipts, copies of emails, etc.  I need to get a bunch of prints made of photos of the progress as well.

Steve.

[NathanStewart]

SCTA is not going to measure thickness, or drill to see what you used.
 

no, we usually won't make you drill but we do have a new sonic tester for a reason.  some new cars and a lot of old cars get checked.  at speed week 2010 a car was permanently red tagged on the spot during tech for being undersized. 

and yes, 1 5/8" x.120 is fine.

[Ron Gibson]

  At Speed Week 2010, my tubing was sonic checked, because of age and possible interior rust.
  Car was new to me but 22 years old. Passed with flying colors, good to know it's as safe as needs to be.

  Ron

[Tman]

With the variations in wall thickness I would never build to the lowest common denominator. With a digital caliber my tubing can measure from .144 (advertised?) down to thinner than .134. Thats a big spread. I am also going to disect a bend and see where it is at thickness wise.

[Peter Jack]

Trent, take a look back. At one point Willie did a bunch of bends and measured the insides and outsides. If I remember correctly he did some direct measuring and he also had a sonic tester.

Pete

[Tman]

Trent, take a look back. At one point Willie did a bunch of bends and measured the insides and outsides. If I remember correctly he did some direct measuring and he also had a sonic tester.

Pete

Thats right, I forgot that I had dug up that thread a while back!

HEre it is so other folks can see it

http://www.landracing.com/forum/index.php/topic,4846.0.html

[Peter Jack]

I enjoyed going back over that thread. There was a lot of really good information. The one thing I found frustrating was that Panic only left his posts up for a limited length of time and then deleted them. As I remember, they really did contribute to the discussion but it spoils the integrity of the topic when they're allowed to be removed. For that reason I'd like to see an even shorter time allowed for revisions to posts so that spelling and phrasing errors can be corrected or small additions made but that wouldn't allow removal of the basic post. I'm not sure it's possible but it's something to think about.

Pete

[Tman]

I enjoyed going back over that thread. There was a lot of really good information. The one thing I found frustrating was that Panic only left his posts up for a limited length of time and then deleted them. As I remember, they really did contribute to the discussion but it spoils the integrity of the topic when they're allowed to be removed. For that reason I'd like to see an even shorter time allowed for revisions to posts so that spelling and phrasing errors can be corrected or small additions made but that wouldn't allow removal of the basic post. I'm not sure it's possible but it's something to think about.

Pete

I am the opposite, I would rather see you able to edit indefinately but post with a freaking spine and not delete comments! Works fine on the other dozen or so boards I visit. 


I am also a proponent of the search. You are right, tons of good info in that thread.