... . 4. OEM is available. Specification: Product nameScrew, Different function of Screws BrandWDMaterialCarbon Steel (35#, 45#), Alloy steel (35crmo, 40cr)SizeM3-M40 ... , 5.8, 6.8, 8.8, 9.8, 10.9, 12.9 gradeStandardGB, BS, ANSI, JIS, DIN Surface treatmentBlack oxide, Zinc ... .2. Non-standard product is available. Screw, Different function of Screws