About this item Premium Material: 3/16 & 1/4 zinc-plated brake line are made of alloy steel to prevent oxidation. All brake pipe fittings are made of anti-rust brass, which has a long service life. . ANTI-RUST - brake lines are made with unique rust corrosion proofing technology. The lastest double wall galvanized steel tube brake line is better than standard steel tubing with corrosion resistance. .