DIN 7981 Stainless Steel Pan Head Phillips Self Tapping Screw
A self-tapping screw is a screw that can tap its own hole as it is driven into the material. For hard substrates such as metal or hard plastics, the self-tapping ability is often created by cutting a gap in the continuity of the thread on the screw, generating a flute and cutting edge similar to those on a tap. Thus, whereas a regular machine screw cannot tap its own hole in a metal substrate, a self-tapping one can (within reasonable limits of substrate hardness and depth). For softer substrates such as wood or soft plastics, the self-tapping ability can come simply from a tip that tapers to a gimlet point (in which no flute is needed). Like the tip of a nail or gimlet, such a point forms the hole by displacement of the surrounding material rather than any chip -forming drilling/cutting/evacuating action.
|GRADE||CHEMICAL COMPOSITION1(%MAXIMA UNLESS STATED)||NOTES||ALTERNATIVE NAMES|
|A1||0.12||1||6.5||0.2||0.15/0.35||16-19||0.7||5-10||1.75-2.25||2 3 4||303S31,303S42,1.4305|
|C4||0.08-0.15||1||1.5||0.06||0.15-0.35||12-14||0.8||1|| ||2 9||416，1.4005|
|F1||0.12||1||1||0.04||0.03||15-18||10||1|| ||11 12||430，1.4016，430Ti，1.4520，430Cb，1.4511|