Main hoop main hoop support bars door bars.
Chromoly roll cage wall thickness.
The cage we selected comes with.
Round 4130 chromoly steel tubing 1 63 o d.
But you have to use larger sticks of tubing or more wall thickness and it costs you weight.
A nascar cage is built completely differently than an average offroad cage.
The chromium adds strength hardenability and a level of corrosion resistance to mild carbon steel though chromoly is not as corrosion resistant as stainless steel.
The cage chassis are one in the same.
Round tubing 3 4 x 058 chrome moly steelsold in 8 foot lengths comments box at checkout.
You can make a cage out of mild steel dom tubing that is just as safe as a chromoly cage.
Also while a chromoly cage is typically lighter due to its lower minimum wall thickness it can only be tig welded while mild steel can be tig or mig welded though the welds need to be clean complete without holes and show no signs of grinding.
All roll bars cages constructed of 4130 chromoly tubing must be welded using an approve tig heliarc process while mild steel must be done with an approved mig wire feed or tig heliarc process.
Chromoloy tubing is made from a family of low alloy steels that contain chromium and molybdenum sae 4130 or 4140 along with the iron carbon and other elements.
As pointed out above in the nhra regulations the minimum wall thickness on mild steel is more than that of chromoly to achieve the same result and.