Fastener driving tool assembly

摘要

The fastener includes an elongate shank (22) having a thread (24). An end of the fastener (20) is provided with an enlarged or headed portion (26) having a recess or drive socket (28). A drive tool (30) has an end portion (32) that is configured to a complementary shape to the socket (28) and is thus engageable so that the drive tool can impart driving forces to the fastener (20). The recess or socket (28) has an internal configuration which is defined by a series of alternating elliptically curved lobes (34) and elliptically curved flutes (36). The lobes (34) are directed radially inwardly while the flutes (36) are oppositely formed.