This standard specifies the types, dimensions, and technical conditions of hexalobular countersunk head self-drilling and self-tapping screws. This standard applies to hexalobular countersunk head self-drilling and tapping screws for automobiles with thread specifications of ST2.9~ST6.3.
QC/T 873-2011 Referenced Document
GB/T 3098.11 Mechanical properties of fasteners--Drilling screws with tapping screw thread
GB/T 3103.1 Tolerances for fasteners--Bolts,screws,studs and nuts