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Topic Review (Newest First)
01-27-2009 11:13 AM
BAILEIGH Anyone have any other question about tube rolling or bending?
01-06-2009 09:56 AM
scrimshaw Also meant to say that the ID of a pipe remains consistent throughout ie at joints the pipe gets bigger or it is flanged and bolted so there is minimum interuption to fluid flow whereas a tube is usually sleeved on the inside as we don't care about ID on a tube.

Sorry Baileigh for interupting your thread just wanted to clarify my post.
01-06-2009 08:59 AM
scrimshaw
Quote:
Originally Posted by steve392
Incorrect. Piping meant for fluid transfer has a nominal diameter and is manufactured to a standard outside diameter. The wall thickness (schedule) varies which means that the inside diameter changes. For example, all 2" pipe has an outside diameter of 2 3/8", which is the nominal diameter. The wall thickness varies from .154" for sch. 40, to .218" for sch. 80. There are also lighter and heavier thicknesses available.
Tubing also has a standard outside diameter, however it is the actual diameter. 2" tubing is 2" o.d., and also comes in varying wall thicknesses.
As for strength, a common carbon steel piping grade is ASTM A53 Gr. B which is seamless and has a tensile strength of 60,000 psi. A common tubing grade as used for roll bars and cages is 4130 Chrome Moly steel with a tensile strength of between 81,200 and 97,200 psi.
Just wanted to clear that up....

Steve
Hi Steve

I feel like we are arguing semantics and while I can't fault you for what you wrote I still think what I wrote was correct. Yes - within a specified size the OD does not change but the specified size doesn't really correspond to the OD it has to do with the ID at a certain wall thickness.

For example a 1 inch pipe is made to carry an approx. amount of fluids so it's inside diameter is sized for that amount. Sch. 40 has an ID of 1.049" and sch80 has ID of 0.957 both very close to 1" but it's OD is 1.315.

A 10 inch pipe has an ID of 10.020 (sch 80) and 9.750 (sch40) so the ID is still close to the specified pipe size whereas the OD is 10.75" - much bigger than 10 inches.

The specified size originally was directed at ID rather than the OD at these wall thicknesses because pipe is manufactured for fluid flow, although like many codes, original guidelines have become blurred with new technologies, materials and manufacturing methods.
01-06-2009 05:19 AM
steve392
Quote:
Originally Posted by scrimshaw
Pipe is a vessel for carrying fluids. It is made to an INSIDE measurement and this measurement should remain consistent regardless of the outside measurement.
Incorrect. Piping meant for fluid transfer has a nominal diameter and is manufactured to a standard outside diameter. The wall thickness (schedule) varies which means that the inside diameter changes. For example, all 2" pipe has an outside diameter of 2 3/8", which is the nominal diameter. The wall thickness varies from .154" for sch. 40, to .218" for sch. 80. There are also lighter and heavier thicknesses available.
Tubing also has a standard outside diameter, however it is the actual diameter. 2" tubing is 2" o.d., and also comes in varying wall thicknesses.
As for strength, a common carbon steel piping grade is ASTM A53 Gr. B which is seamless and has a tensile strength of 60,000 psi. A common tubing grade as used for roll bars and cages is 4130 Chrome Moly steel with a tensile strength of between 81,200 and 97,200 psi.
Just wanted to clear that up....

Steve
01-05-2009 07:47 AM
BAILEIGH
Quote:
Originally Posted by Chevrolet4x4s
Hello Shane
Welcome to Hotrodders.

What would you suggest for the 4 link bars on an coil over sprung(front and rear) rpu in the neighborhood of 1500-1800 lbs.
Shane
Not sure on that one.
01-03-2009 06:50 AM
RPM
Quote:
Originally Posted by BAILEIGH
That is an odd application. What are you building?

Are you sure you are measuring your desired CLR correctly?
We build a lot of hairpins for the front and rear suspension. We have a good customer that is having trouble with the 7/8"-.156 wall tube hairpin bending in higher HP applications. We make a lot of the 1" stuff.
01-02-2009 06:24 PM
Chevrolet4x4s Hello Shane
Welcome to Hotrodders.

What would you suggest for the 4 link bars on an coil over sprung(front and rear) rpu in the neighborhood of 1500-1800 lbs.
Shane
01-02-2009 01:29 PM
powerrodsmike It was more of a general question, I usually experiment with stuff and learn as I go.
As I said in a previous post, I have a hossfeld # 2, and that does tubing bends much like a rotary bender, if you have the 180 degree die set for a given tube size. The die set comes with a die, and matching back block and draw block, which holds the tube tight to the die while bending, supports the outside of the tube, and is designed to create tension on the tube while it is being bent.

I know their technology is good , as some of the listed bends for various die sets are pretty tight. They list the material, OD and minimum wall thickness and a bend centerline radius for all of the dies they sell.
For example, their 28643 die set will bend 1 5/8 10gauge DOM or ERW 1020 tubing in a 180* with a 3 1/4" CLR.


Later, mikey
01-02-2009 12:06 PM
BAILEIGH
Quote:
Originally Posted by powerrodsmike
Is there a chart or calculation that can tell you what the minimum bend that can be attained using a given wall thickness? Using a rotary draw type bender, and not a mandrel bender?

Later, mikey
Not really......minimum wall thickness vs.. CLR will all depend on what style and what quality of tube bender you have.

Here is an example:

Some rotary draw benders provide little or no outside support on the tube as it is being bent. So the bend quality will be different than a bender that has a nice counter bend die assembly that forces the material into the die set. I can only speak for our benders, but I'll try to answer your question.

What are you building? What size of tube are you trying to bend? What is the material?
01-02-2009 11:45 AM
powerrodsmike
Quote:
Originally Posted by BAILEIGH
It all depends on the wall thickness of your tube. The thicker the tube, the tighter you can bend.
Is there a chart or calculation that can tell you what the minimum bend that can be attained using a given wall thickness? Using a rotary draw type bender, and not a mandrel bender?

Later, mikey
01-02-2009 11:14 AM
BAILEIGH
Quote:
Originally Posted by powerrodsmike
IIRC, the minimum centerline bend radius that I could get out of my homemade dies was about 3.5 times the OD of the tube. Anything less and they'd kink.

Later, mikey

It all depends on the wall thickness of your tube. The thicker the tube, the tighter you can bend.
01-02-2009 11:13 AM
BAILEIGH
Quote:
Originally Posted by RPM
What are your thoughts on bending 1" DOM with a .219" wall on a 2" C/L radius? I have a Jd2 bender and they don't offer a die for it. I can make a die, but did not want to go to the trouble of making it to find out that heavy tube won't bend that tight.
That is an odd application. What are you building?

Are you sure you are measuring your desired CLR correctly?
01-02-2009 11:11 AM
BAILEIGH
Quote:
Originally Posted by protrabbi
hi shane
i just managed to get youre model rdb300 here in the uk a couple of weeks ago.
of to give it a try today making a roll cage for an english ford pop.

have used it a bit to do A arms and seams a superb machine.
a lot user friendly than my manuall bender.
a question regarding die raduis.
i have a 1 5/8" 6"clr for doing the cage but did try to bend an offcut of stainless 1 5/8" x 1.5mm wall but as you stated it wrinkled the tube.
what would be the ideal die radius for doing thinwall stainless in 1 5/8".

only ask about that sise as i wouldnt mind doing a set of headers.

to anyone else using any bender the bend tech software is superb.got the se version here.
thanks
wayne

Hello Wayne,

Good to hear from happy customers.

1 5/8" x 058" wall stainless will kink unless you have die set that is at lease a 7.75" CLR (centerline radius) You will not be able to make hearders with your bender. Headers require a mandrel bender.
01-02-2009 07:08 AM
BAILEIGH Hydraulic power is a no brainer after a couple sticks.
01-02-2009 07:03 AM
BAILEIGH
Quote:
Originally Posted by Mike H
Mike, JD2 has a rotory bender like the 100. I have the model 3 that I finaly converted to hydroulic last summer. Bend some .083 1 5/8" CM manual for a few years and you get worn out. .125" wall mild steel is a breaze after the CM and quite a bit less spring back.

I realy like the bend tech pro software I have been using for about 5 years now. I would recomend it as an add on to anyones bender.

Mike

Yes...bending Chromolly on a manual bender gets old after a while. An upper body work out.
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