Abstract: A mold within which molten metal is sand cast, is provided with strategically located chill plates which shape and rapidly cool the molten metal at predetermined locations for hardening those locations relative to the hardness of the remainder of the casting. The mold is formed of a cope and drag frame type flask within which sand is compacted to form the sand cavity. Plates are arranged transversely of the casting cavity and are secured to portions of the flask frame for dissipating heat through the plates and out through the frame. The plates are fixed to portions of the flask and are arranged in opposing pairs which are aligned, coplanar, in abutting relationship. Each plate of each pair is provided with a notch, aligned with its opposite plate, for encircling the portion of the casting to be chill hardened. The pattern used for forming the cavity extends through the aligned notches and between the plates to form the composite sand and metal plate casting surface in the cavity.