General Order 64-A
Additional Construction Requirements For Tower Lines
65.1 Tower Members
Tower members shall have thickness of metal not less than the following:
Galvanized steel: Legs, 3/16 inch; other members 1/8 inch.
Painted steel: Legs, ¼ inch; other members, 3/16 inch.
All iron or steel members of towers and all hardware subject to injurious corrosion under the prevailing conditions shall be protected by galvanizing, painting or other treatment which will effectively retard corrosion.