Mckay 308/308H Sterling AP description: Excellent for use on Type 301, 302, 304, 305 and 308 base metals. It is specially formulated with more than .04 carbon to provide maximum elevated temperature strength. Has a smooth running arc that results in a uniform weld bead that is flat to slightly convex. It is also idea for use as a intermediate layer prior to the deposit of hardfacing materials. Yields a concave weld bead that is smooth and refined.