what size tubing for frame

i was wondering what size tubing to use on making a whole frame i need to know what size tubing to use and wall thickness i have a 86 isuzu pup that im making the frame for and i was thinking of 2 1/2 tubing with a 1/4 wall wat do you guys think need to know soon gunna buy the metal today or tomarrow thanks

The 2.5" will work good man, but I woul use 2x3 or 2x4 with either 3/16" or 1/4" wall

2x3 or 2x4 1/4 wall

definetley no need to use 2x4 on a minitruck. I doubt you'd be able to do a SFBD too easily using 2x4. I guess you could always go with 2x4 from the cab back for looks or whatever, but you have to consider the weight factor vs 4 cylinder motor.
When built with proper crossmembers, 2x3 3/16" wall will be more then adequate. Just make sure you use it with the 3" as the vertical height.

^^^thats all you need to know right there...

you can use the 2 1/2 square under the cab.

how about for round tubing or circle aaah you guys know what i mean and thanks for the info

I'll chime in here. For frame work, make sure you use 1/4 wall TUBING. Not pipe. There'll be people who'll argue that they're the same thing, but from an engineering perspective, they're entirely different. The two are made different and used for different purposes. Tubing is designed to be a structural metal, while pipe is intended for substances to pass through. Think pressurized substances.Anyhow, I'm not here to settle an argument. For a full frame end to end,I'd use 2.5 od tubing with a 1/4 wall.And make sure you take pics and post em up for all to see.Good luck!

my tube frame is 1.75 x .120 dom tubing..if i had to do over i would do chromo but thats just being overbuilt..if u want pics send me ur email.late

2 1/2" round tube is not good material to use for a frame, assuming its going to be a single rail. the torsional stiffness of the frame is going to be low, which means there will be a great deal of twist in it, unless you are going to build a sweet rollcage for the entire truck.