Made of carbon steel, which has higher hardness, corrosion resistance and rust resistance.The self-tapping screws can drill well into the wood, sheet metal and other surfaces. The thread can reduce the resistance when screwing in and prevent cracking.It can also connect metal hardware to the wood well because the threaded rods provide good retention in the wood.Widely used in various industries such as manufacturing, construction, engineering, and assembly.Specification:Material: Carbon SteelFinish: Black OxidePerformance Grade: 8.8Thread Size: M6 x 20mmThread Pitch: 1.81mmHex Width: 4mm / 0.16"Screw Head Size: 10.2 x 3mm / 0.4" x 0.12"(D*T)Package Content: 50pcs x Hex Socket Self Tapping Screws.