This round bar chisel is the sort usually used by stone masons; its thick body can withstand repeated heavy blows without bending or becoming shorter.  A chisel such as this could be used either to destroy a monument by cutting stone into size and shape for reuse, or to begin restoration on a heavily damaged piece. This XIXth Dynasty chisel, found in the ruins of the XIth Dynasty Temple at Deir el Bahari, might have been used for either.

A chisel of copper would have needed frequent re-sharpening.  In Ancient Egypt, chisels were issued to the workmen, and frequently weighed and examined to ensure that no valuable copper was pilfered.  Sometimes valuable tools were buried in pits as Foundation Deposits at temple, but the excavation reports written by H.R. Hall in 1912 suggest that somehow tools, baskets, and even remains of the workers' lunches from the time of Ramesses II's restorations were simply 'left' on the site, "lost, or perhaps thrown away."