This standard specifies the types, dimensions and technical conditions of hexalobular pan head self-tapping screws for plastics. This standard applies to hexalobular pan head self-tapping screws with thread specifications NST3 to NST6 that match the bottom holes of plastic nuts or similar parts.
QC/T 878-2011 Referenced Document
GB/T 3098.5 Mechanical properties of fasteners.Tapping screws*, 2016-02-24 Update
GB/T 3103.1 Tolerances for fasteners--Bolts,screws,studs and nuts
GB/T 6188 Hexalobular internal driving feature for bolts and screws*, 2017-12-29 Update