We present results of single shot ablation experiments for a variety of metal samples (In, Al, Cu, Mo, W, Ti) using visible, nanosecond lasers at fluences up to approximately 104 J cm-2. At low fluences, usually less than 102 J cm-2, small amounts of material were removed and removal was approximately uniform across the ablation crater. As the fluence increased above approximately 102 J cm-2, substantially more material was removed and a conical pit developed in the center of the ablation crater. The appearance of these conical pits is consistent with material removed by phase explosion mechanisms. In this paper, this ablation phenomenon will be investigated by presenting the crater morphology as a function of fluence. Consequences for micromachining with visible, high repetition rate, nanosecond lasers will be discussed.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.