SAE ARP1947B

This document covers the recommended practice for determining the acceptability of the dendrite arm spacing (DAS) of D357-T6 aluminum alloy castings required to have tensile strength not lower than 50,000 psi (345 MPa). To apply this method, at least two coupons used for DAS measurement and tensile testing, shall be attached to the casting in locations as defined by the cognizant engineering organization. Areas of the casting which require DAS control must be accessible for surface DAS measurements.