We report results of vertical impacts of aluminum projectiles into quartz sand. The impacts were performed at velocities of 35 to 830 m/sec with a single stage powder gun. Morphology of craters formed in loose sands is generally conical, whereas morphology of craters formed in self-compacted sands varies from a flat-floor type to a double ring type, with increasing impact velocity. The present data together with previous experimental data and Dienes and Walsh's 'late-stage equivalence' indicate that crater diameter is expressed by a function of the 'late-stage effective energy' but not of the impact kinetic energy. The diameter of a crater formed in a noncohesive sand was found to be proportional to one-fourth the power of the late-stage effective energy. For a general impact cratering in a target with a finite strength, the diameter, D, versus impact velocity, v relation is written as follows: {(v/v*)+((v/v*))2}=K{(D/D*)4+(D/D*)5/2} where v* and D* are normalizing values of the impact velocity and diameter, and K is a constant related to target and projectile properties. The relation suggests that there are four regimes in crater diameter versus the kinetic energy relation.