Alloy steel grade 12.9 black DIN912 allen head screws are high-strength screws made from alloy steel with a grade 12.9 rating. They are coated in a black finish for corrosion resistance and aesthetics. The screws have an allen head,hex socket head cap screw which requires an allen wrench or hex key for installation and removal. DIN912 refers to the German industrial standard for this type of screw,self tapping bolts for steel hex socket cap screw ensuring consistent dimensions and quality. These screws are commonly used in applications that require high tensile strength self tapping bolts and resistance to wear and tear, such as automotive,self tapping concrete bolts stainless steel hex head screws machinery, and construction industries.