thread rod din 975 M4-M30 black plain and zinc. Size range: M3 to M30 thread rodMaterials: carbon and alloy steel Platings: black oxide, zinc, chrome, galvanized, nickel, dacromet, delta-tone, geomet and ruspert Grade: 4, 6, 8 and 10 good quality and good pricegood quality and good price. thread studs