Notes on bolted connections with self tapping screws - AH00.00-P-0007-01SF

General: 

Terms: 

"Self-tapping" is the generic term and it comprises both "thread-forming" and "thread-cutting". The following covers only thread forming screws that meet the globally applicable "TAPTITE" standard.

Properties: 

Thread forming screws create a screw-in thread in prefabricated core holes via typical conical crests without cutting.

The screw-in threads created by thread forming screws can easily take up screws with a metric ISO thread (standard screw).

Automatic centering during initial manual installation of self-tapping screws is given.

Repair and replacement solutions: 

• It is permissible to reuse an existing or other used thread forming screw.
• The installation of a new  thread forming screw into an already existing  screw-in thread is not permissible.
• It is permissible to replace a thread forming screw with a new or used standard screw. The length of the standard screw must be three threads (groove tip) shorter than the length of the originally installed thread forming screw.