At our trash can factory, the thickest gauge we work with for internal liners is 7-gauge steel (about 4.5 mm). This material is reserved for commercial and industrial applications where abuse is the daily norm. A 7-gauge liner will not easily dent, buckle, or flex under constant compaction pressure, heavy bag loads, or accidental impacts from maintenance equipment.

For a commercial plaza, I would strongly recommend our "Plaza Guard" line with a 7-gauge galvanized steel internal liner. It's welded with full-penetration seams, gets a corrosion-resistant baked-on finish, and is engineered to fit inside a 12-gauge outer shell. The combination can handle virtually anything the public throws at it — including hot ashes, wet waste, and even the occasional misdirected shopping cart. If you'd like, we can also reinforce the bottom corners with an additional steel doubler plate at no extra cost for your first pilot order.

That's the straightforward answer: our maximum is 7 gauge, and it is genuinely built for real abuse. Want me to send over a spec sheet with thickness tolerances and liner dimensions for your plaza layout?