Depends on the material its made from. Aluminium containers usually 3-4mm
Mild steel 2-3mm
Corten steel 2-3mm
Varying thicknesses dependent upon manufacture. Containers made in china are usually thinner than container built in europe. We usually conduct our container fire fighting drills on 2mm mild steel plate.
Thanks everyone, when I googled it thickness appears to be between 1.5 /3.0 Corten steel, there is a huge industry involved in their fabrication, The Big Box company being one of them, but the information I needed appears to be pretty thing on the ground. I will only be cutting holes for windows and doors.
Not much use for the thicknesses but might be of some use for future ref. This is what’s stuck inside mine, it’s a Genstar 1994 so there is just rust missing from the materials list
From the way the travellers passing through went though the side of a local ground keeping business containers rather than use the door in the middle of the night, not thick enough!