hard hammer
“Hard hammer percussion - that is, striking the tool with another stone to remove flakes." Whittaker 1994., 27​ The following are indications of the use of a hard hammer or percussor:

-unlipped and often large butt and pronounced bulb of percussion.

-a clear cone and marked point of percussion.

-pronounced conchoidal fracture marks on the bulb.

-clear concentric percussion rings and fissures.​
see Ohnuma & Bergman 1983.



see movie basic flint knapping with hard hammer