Large graduated tamping rod - 5/8 in. diameter 24 in. long concrete testing graduated tamping rod. round straight steel rod used with concrete cylinder molds, slump cones, and unit weight tests. both ends are rounded to a hemispherical tip. plated for rust resistance and stamped with a 6in scale in 1/4in increments for easy measuring. meets astm c138. *Product images are representative only.