What would be a good power saw?

This trap involved two victims, Adam Faulkner and Lawrence Gordon, who had both been confined in a grimy industrial bathroom. Both were chained by the ankle to pipes at opposite ends of the bathroom. Also present in the room was a dead body, holding a gun, sitting in a pool of poisoned blood, just out of reach of the two prisoners. One of the prisoners, Lawrence, received a bullet, with which to load the gun and kill the other prisoner. He was told that if he didn't do this by a certain time, his family would be killed, and he'd be left to rot. In order to reach the gun, however, he had to saw off his own chained leg with a hacksaw, hidden in the room. The other victim, Adam, would have to try to escape by sawing off his own leg and leaving. It should also be noted that the hacksaw's strength is only enough to saw through flesh. Both tried to find alternatives, but could find none. Desperate to save his family, Lawrence was forced to saw his own leg off and retrieve the gun. He attempted to fatally shoot Adam, but closer inspection revealed that Lawrence only shot him in the shoulder. He then crawled out to find help. Adam, however, remained trapped. It is assumed that Lawrence either died from his wounds or could not relocate the bathroom, because the corpse of Adam was found in the Nerve Gas House in Saw II. Jigsaw later told Adam that the key to unlock the chains was in the bathtub in which Adam had woken up in. The bathtub was filled with water at that point, and Adam accidentally drained it when he woke up, unwittingly sending the key into the drain. In Saw III, it is revealed that Adam did not in fact die of starvation or dehydration after being locked away, but by suffocation. Amanda, feeling terribly guilty, decided to help him by sneaking into the bathroom and placing a strip of plastic wrap over his head, bringing him to a somewhat more timely death.