Exhaust Thickness - Decat Pipe

[downsyndromedhorse]

Anyone know the thickness of the exhaust pipe?
Its for the catalytic convertor, just a thought to making a decat pipe out of an old exhaust.
My mates dad works in a bus & lorry workshop so he could knock one up pretty quickly if i get him the pipe.

Also with the decat pipe, is this a straight pipe? Or is it bent to fit? Not had a look under the car at the cat as i dont have my ramps at home atm.