Assertion: hard hammer | /r/HasProperty | necessary
Facets:
value: to prepare the percussion platform
type: PURPOSE
value: in the case of the cores
type: OTHER
Source sentences:
text: Other times, in the case of the cores, although the extraction of flakes or sheets was done with a soft or pressure hammer (see below), the hard hammer was necessary to prepare the percussion platform and eliminate protrusions that could disrupt the operation.