Square vs. Round?

[Kumofo]

I am creating plans for building a go-kart. For the frame should I use Square or Round stock? Which grade? Specification? O.D.? I.D.? Thickness?:rolleyes3:

 

[fluxcored]

From general fab work:
1. If you do'nt have a level surface to work from then use square.
2. If you do'nt plan to use bends in the round tubing then use square.
3. If you're not used to welding then use square.
4. If you want a fast build use square.

As I never built a kart before I can't suggest sizes - but I'm going for 1" OD with 0.08" wall.

 

[ryf]

I used both, my roll bars are mostly 1/2" schedule 40 pipe (sold as handrail without the black coating), the frame is 1 1/4"x 1 1/4 x 3/16 thick square.

before you get into this too deep, is this a street type cart or offroad?

mines offroad designed for getting rolled, thick and heavy, lots of triangulation, and lots of pipe. the 1/2" pip has 3/4"ish ID and 1 1/8"ish OD. my main roll bar is 1 1/4" ID pipe actual is like 1 5/8" ID, and is almost 2" OD! my cart is about the size of those new Smart Cars, so it scales well.

I would dare say only a seriously powered street cart would need tube that thick and size.

no matter what your building, I would recommend a hybrid of the two, make the center areas (where things get mounted) square, and use round to make it pretty, square is easier to work with for the frame, but round looks better, but a hybrid would give you alot less joint grinding/cutting plus you could have a nice square (straight) frame. I vote errr... both?

examples from my build, first on is with the old front end but you can easily see the square center, and the second is the new front end, still see square center, not shown is my new rear suspension, but thats ok.

 

[Jerryburger]

I always wondered which was better, too. I know which is easier for a Dumb_ss like me. Square!

 

[Kenny_McCormic]

Square is 1000000000000000x easier to work with and you dont need a tubing bender.

 

[Kumofo]

Sorry for not responding to your comments. I have been away from my computer for a while. It looks like since I am a beginner when it comes to welding I am going to weld a sqaure frame. Maybe later when I get better at welding I will bend and weld round. Thanks everyone for the help!

 

[kibble]

Harbor Freight has a decent hydraulic bender that works well.

This is what I used to do all the bends on my kart.

 

[spikeman]

so is there any other way to bend round tuding other than than using a bender.

 

[jr dragster T]

so is there any other way to bend round tuding other than than using a bender.

There are ways to get it done cheaper. But tubing bending is a art and must be done right. You need those speicel die's to bend the materiel around. I have seen some people just bolt the die to a bench and attach the tubing to the bench and heat it up and just wrap it around. But this will be pain-staking and it will take along time to do.

 

[Cotmullion]

I've always used square for my projects, for the simple fact that it is easier. Round is lighter though and does sort of look better, but to join round tubing at right angles you need to fish mouth the end.

 

[Kumofo]

So, with all you'als help I have decided I will just use square for now until I learn more metalworking tricks. I was thinking of using square 1.5 o.d, and about .065-.120 thickness, however I do not know the grade/specification I should use.

 

[Ferrari motors15]

The square are very easy to form and draw oles.

 

[ryf]

lawdy, 1.5" is big, and .120 is give or take 1/8", for that size, mild steel is fine, and plenty strong. I might recommend 1.25", a little cheaper, and plenty strong, alot of guys on here use 1", so unless you are going big like mine, I wouldn't pay for that extra weight! mines 48"wide, and 8ft4" long!

 

[Kumofo]

I'll have to price the steel out. I work for Fastenal so I am sure my employee discount should be healthy towards a purchase. 1 1/4OD, .080T, should be sufficient for a light weight off/road go-kart.

 

[Ferrari motors15]

It,s ok but you ave to do great welds

 

[nickzom]

I think, and I stress think, that round tubing has no stress points and square has on at each corner.