Uniform 0.028" wall thickness, 1/2" OD, for maximum pressure tolerance. This 90/10 copper-nickel tubing meets SAE standards J1047 and ISO 4038 for use as brake lines in the U.S. and internationally. The specific alloy is 88.6% copper, 9.2% nickel, 1.4% iron, and 0.8% manganese.. Copper-Nickel tubing is strong like steel tubing, but with the added benefits of being almost completely corrosion resistant and extremely easy to bend and work with. 90/10 copper-nickel has been used on European vehicle brake systems since the 70's. Some of these high-end makes include: Volvo, Audi, Porsche, and Aston Martin. Also ideally suited and compatible for use in fuel and transmission systems. 90/10 copper-nickel is perfect for vehicles exposed to road salt and other corrosive environments, where a longer-lasting line is required, and/or where OEM replacement for high-end makes and models is desired. 90/10 copper-nickel does not rust, it is DOT approved for brake systems, it bends 58% easier than steel tubing