What's the stronger tube?

[SpasticR450]

Which would be the better one to buy for strength?

(3/4") ROUND MILD STEEL DOM TUBE 1026 3/4 X 0.156
0.750 in. Outside Diameter
0.156 in. Wall Thickness
0.9897 lbs. per foot

OR

(INCH) ROUND CHROMOLY TUBE 4130N 1 x 0.083
1 in. Outside Diameter
0.083 in. Wall thickness
0.834 in. Inside Diameter
0.8129 lbs. per foot

[CJM]

chromoly is but its much more $$

[SpasticR450]

Originally posted by CJM
chromoly is but its much more $$

But what about wall thickness? It's 0.083 while the normal steel is 0.156. Is the chromoly one still stronger?

[250x_kyle]

chromolys still stronger. wall thickness is not the only factor. the structure of the steel itself is based off of forming, cooling cycles and what is added into the mix.

chromoly steel has chromium and molybdenum in it. and depending on how the tubing is formed and heat treated can grately affect its structure. theres a curve graph with heat treating. plain jane steel has alot less room for error in heat treating making it harder to get the correct structure. chroimum and molybenum in the mixture give more room for error in the heat treating process. so if the steel is in a furnace at roughly 1500 degrees depending on how it is cooled and what it is cooled with depends on the structure of the steel. with less room for error it can greatley affect wether its a martensite, bainite, fine pearlit, or coars pearlite structure.

if you plan on doing a project with the tubing you will need a good tubing bender so it doesnt kink the tubing. a tubing notcher, and chromoly is best tig welded over mig. do not quench chromoly to cool it down faster.

[beastlywarrior]

the chromoly will be stronger and lighter

[CannondaleRider]

Chromoly is also easier to weld well, then mild steel..... just don't quench it, let it cool naturally.