SAE J78

Steel Self-Drilling Tapping Screws

English 1998
2.001
Detailed Information

1.1 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.

1.2 Screw Types and Application—The two types of self-drilling tapping screws covered by this document are designated and described as follows:
1.2.1 TYPE BSD—Type BSD screws shall have 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.
1.2.2 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.

1.3 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.

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