Assertion: head screwdriver | /r/HasProperty | designed in 1930
Facets:
value: originally
type: OTHER
value: for use with mechanical screwing machines
type: PURPOSE
Source sentences:
text: Cross-head or Phillips screws have an X-shaped slot and are driven by a cross-head screwdriver , designed originally in the 1930s for use with mechanical screwing machines, intentionally made so the driver will ride out, or cam out, under strain to prevent over-tightening.