Which type of steel used to build the chassis

[Maurizio Lazzeretti]

Hello,
I want to know, if possible what is the classification of the steel used for the construction of the car chassis.
I know that the classification is 304 or 304L stainless steel, which is that of steel normal?
Thank you

 

[Mike Pass]

Which car?
Original car, Gelscoe, ERA, SPF - mild steel monocoque
KVA,GTD, Tornado, Southern GT, MDA, GT Forte, etc. mild steel tube frame
CAV - stainless steel monocoque
RCR- aluminium monocoque

Cheers
Mike

 

[Maurizio Lazzeretti]

Thanks Mike .
I was thinking of a tube frame chassis scratchbuilt .
So mild steel or stainless steel .
What should be the thickness of the steel tube used ?
Thank you.

 

[Mike Pass]

Not stainless for a space frame chassis. Too heavy and prone to cracking at the welds. The thickness of the mild steel tube would depend on how heavy or strong you want it to be. Also the size of the tubes will be different in higher or lower stress areas. Generally wall thickness would be around 1.5mm for the light sections and thicker for the bigger sections. Most replica chassis use square or rectangular erw tubing.
Cheers
Mike

 

[Jack]

Not stainless steel please! As has been noted, cracking at the welds will form.
Mild steel in 2mm thickness is generally good all around for a space frame. Don't forget gussets as well.
The slightly heavier tubing will be easier to weld.

 

[Dutch]

Here's an interesting read concerning a stainless constructed race chassis.
Paul Dudiak's McKee Mk12c Formula A / Formula 5000 Racecar

 

[Andy Sheldon]

Just to complete the list.

Tornado Monocoque Chassis - Aluminium Honeycomb or Carbonfibre Honeycomb

Thanks

Andy

 

[Michel]

This is a link to aGT40 replica scratch built chassis in stainless steel ;
http://www.gt40s.com/forum/gt40-build-logs/32106-riviera-scratchbuilt-gt40.html

But as stated before no need of stainless material ; mild steel is far enought strong and easier to weld if not TIG welding skills and easier to source in any dimension needed for rectangular tubes and flat steel brackets .
A good blast sanding after finishing the welds and then a serious powder coat or a serious Polyuréthane spray ( 2 components) et voila !!!

 

[John]

Maurizio, i use 40x40x1.6 HRS for the main frame and 25x25x1.6 HRS for the diagonals, full chassis bare weighs 96kg.

kaspa

 

[Maurizio Lazzeretti]

Thank you.
To weld the car chassis, can I use the arc welding?

 

[John]

Maurizio, you can Arc weld it, but i think you will find a Mig a lot easier and neater, not to mention a lot quicker.

cheers Kaspa

 

[Jim Cowden]

An arc would be like using an axe to cut bread.
If you have to buy a welder go a tig, you wont look back.
I have a mig , arc and have not used them in years.

Tig makes you a better fabricator because its not the best at gap filling.

If you get to much heat in a stainless weld it burns the chrome out of the metal and that will cause rust.
Use pickling paste on the welds and it will clean them up.
Stainless pulls like mad when you weld it so you have to do lots of tacks.
When welding around a tube dont change direction or it will pull worse than going around in the same direction.
Stainless is a difficult material to work with.

Jim

 

[Grady]

Which car?
Original car, Gelscoe, ERA, SPF - mild steel monocoque
KVA,GTD, Tornado, Southern GT, MDA, GT Forte, etc. mild steel tube frame
CAV - stainless steel monocoque
RCR- aluminium monocoque

Cheers
Mike

ERA used both mild steel and stainless steel building the monocoque. After #2077 all were stainless steel.