KNURLED FASTENER WITH CUTTING EDGES AND REMOVABLE HEAD

摘要

A novel fastener comprises a head having a recess for receiving a rotary driver, a shank having knurls defined by generally helical grooves and intersecting generally annular grooves, wherein a plurality of the knurls include a lateral cutting edge, and a generally pointed tip. Another novel fastener comprises a head having a rece ss for receiving a rotary driver, a shank having a predetermined diameter small enough so that the head will break away from said shank upon application of a predetermined torque, and said shank having knurls defined by generally helical grooves and intersecting generally annular grooves.