Description / Abstract:
General-This SAE Standard covers the
dimensional and general specifications, including performance
requirements, for carbon steel self-drilling tapping screws
suitable for use in general applications.
It is the objective of this document to insure that carbon steel
self-drilling tapping screws, by meeting the mechanical and
performance requirements specified, shall drill a hole and form or
cut mating threads in materials into which they are driven without
deforming their own thread and without breaking during
assembly.
Appendix A is included to provide a recommended technique for
measuring the case depth on the screws.
Screw Types and Application-The two types of
self-drilling tapping screws covered by this document are
designated and described as follows:
TYPE BSD-Type BSD screws shall spaced threads with drill points
of varying configuration, designated Style 2 and Style 3, designed
to accommodate different panel thickness conditions as delineated
in Section 6.
TYPE CSD-Type CSD screws shall have threads of machine screw
diameter-pitch combinations approximating Unified Form with drill
points of varying configuration, designated Style 2 and Style 3,
designed to accommodate different panel thickness conditions as
delineated in Section 6. Type CSD screws are not subject to thread
gaging but shall meet dimensions specified in this document. They
are intended for application where the use of a machine screw pitch
thread is preferred over the spaced thread.
Head Types-The head types applicable to
self-drilling tapping screws covered by this document shall include
those specified in ANSI B18.6.4, except for slotted head and hex
(nonwasher) head designs which are not recommended for
self-drilling screws.