DIN 7982 ST 5.5 Stainless Steel A2 304 Countersunk Head Phillips Drive Self Tapping Screws CSK Cross Recessed ISO 7050

Description

DIN 7982 ST 5.5 countersunk head phillips/cross recessed drive self-tapping screw is a screw with a flat head & a 5.5mm diameter thread 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). Countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface of the surrounding material (by comparison, a counterbore makes a flat-bottomed hole that might be used with a socket-head capscrew). A countersink may also be used to remove the burr left from a drilling or tapping operation thereby improving the finish of the product and removing any hazardous sharp edges. Ever Hardware also provides custom-made fasteners & other precision components.

Stainless steel does not readily corrode, rust or stain with water as ordinary steel does. However, it is not fully stain-proof in low-oxygen, high salinity, or poor air-circulation environments. There are different grades and surface finishes of stainless steel to suit the environment the alloy must endure. Stainless steel is used where both the properties of steel and corrosion resistance are required. Stainless steels contain sufficient chromium to form a passive film of chromium oxide, which prevents further surface corrosion by blocking oxygen diffusion to the steel surface and blocks corrosion from spreading into the DIN 7982 ST 5.5 internal structure. Passivation occurs only if the proportion of chromium is high enough and oxygen is present.

DIN 7982 Self-Tapping Screws Size Specification: