The 168 metal artifacts collected at Manchu Picchu in 1912 by Hiram Bingham have been examined for evidence that metallurgical artificers worked at this site in pre-Columbian times. Fifteen artifacts have been identified as metal stock, work in progress, or waste materials from metallurgical processes. Bronze was made by alloying metallic tin and copper and was cast into both finished objects and stock for subsequent forging. Hammering was done with stone tools, but bronze chisels were also in use. Silver-copper alloys were worked, but this materials was not held to compositional limits as close as those for bronze. No alloys containing arsenic and relatively little evidence of the use of sheet metal were found.