Icon pistons are made with 2618 aluminum, which is the more ductile alloy normally used in high stress situations. The other alloy, 4032 or VS-75, is less ductile but still strong. This is what the lower cost forged slugs are usually made of. Federal mogul now calls its alloy "FM4032"
Icon is the forged piston line from Silv-O-Lite, which has been making pistons forever and also makes the Keith Black line of hypereutectic pistons.
