17 gauge = 1.422 mm
.055"
19 gauge steel is 1.11 mm thick and 20 gauge is .953 mm thick.
thick
11 gauge steel is 0.125 inches thick.
16 gauge
.0500 inches.
18 gauge is thicker than 20 gauge. 18 gauge is 1.27 mm thick while 20 gauge is .953 mm thick.
Probably 25 gauge, which is .556 mm thick. However, 26 gauge is close too, it is .478 mm thick.
It is .478 mm thick.
.055"
In Imperial standard (swg), 16 g is 0.064" (1.63mm) thick.
4mm sheet metal falls 24 gauge and 25 gauge. 24 gauge sheet metal is 3.175mm (0.125") thick, and 25 gauge sheet metal is 6.35 (0.25") mm thick.