Mich. Comp. Laws § 125.569: Metal gauge.

Sec. 19.

The metal used in all tanks shall be of a minimum gauge, U.S. standard, depending upon the capacity or size as given in the following table:

Capacity Thickness (Gallons) of material 1 to 500 14 gauge 501 to 1100 12 gauge 1101 to 4000 7 gauge 4001 to 10500 1/4 inch 10501 to 20000 5/16 inch 20001 to 30000 3/8 inch

Capacity

Thickness

(Gallons)

of material

1 to 500

14 gauge

501 to 1100

12 gauge

1101 to 4000

7 gauge

4001 to 10500

1/4 inch

10501 to 20000

5/16 inch

20001 to 30000

3/8 inch