This is the tool you need to make the 37° flares required for AN fittings. Standard brake and fuel lines are flared at 45° which are not compatible with AN hardware. This tool forms stronger flares assured by a smooth, even radius formed at base of every flare with its precision machined chamfer. Plus, its also self gauging - just insert tube flush with top of die for accurate flare size. Hardened steel, chrome-finished cone makes exceptionally smooth, high-strength flares with a radius at base offlare – instead of the sharp angle formed by ordinary tools. Slip-on yoke permits use in tight quarters. Allows flaring where there is little space between nut and tube end. Feed screw design provides smooth, easier operation. Positive gripping and self-gauging of tube for exact flare size. Sliding die blocks lock in place by clamp action. Works on 3/16", 1/4", 5/16", 3/8", 1/2" and 5/8" OD tubing such as aluminum, copper, brass and mild steel. Learn more about flaring lines for our automotive fittings by reading our tech article. The Principles of Automotive Fittings.