Jus seeing whats prefered by all the fabricaters here on H-T. I personally like 1/2 flanges because they dont warp as easily but me and some of the part time workers here started gettin into it about what flange thickness would be better.. 1/2 thick or 3/8" thick, my welder says to use 3/8 because its lighter and flange production would go up 50%.... i say 1/2" because they are more heavy duty and dont warp as much when welding....

so i decided to take it to the forums.. what thickness flange do you prefer for head flanges?

 

I like 1/2" for turbo mani and 3/8" for n/a headers.

 

i make all my head, im, turbo and dp flanges 1/2" thick. bov flanges are 1/4" thick and wg flanges are 3/8".

 

I cut all my head flanges and turbo inlet flanges in 1/2". Dowpipe, exhaust, and wastegate flanges are done in 3/8" BOV flanges in 1/4"

It is possible to weld a downpipe flange without badly warping it.

 

1/2" is nice because you can machine it down a bit to make sure everything is flat. it has less chance of warping in the first place, as an added bonus.