When installing a new intake manifold, it is recommended to upgrade your intake bolts; some standard intake manifold bolts won't work depending on aftermarket intake manifolds. These Aeroflow intake bolts are made from chrome moly 8740 for strength. They are coated in a black oxide finish for protection and long-lasting durability. Each bolt features a compact 12-point head, which is ideal for use where space is minimal on most aftermarket intake manifolds compared to the factory bolts with a larger head. Each set includes thick flat washers for optimum clamping pressures to ensure a sure seal.