Made of high quality carbon steel material.The screw type of our product is machine screws.The head style is round.The of our product is woodworking. style is hex socket.Screws bolts nuts assortment kit: includes screw bolts for easy screwing in and out of . With a wrench, it is easy to screw in and not easy to be damaged.Steel screw set bolts: featuring a steel screw in the head design, these bolts are made to match the desired strength and a fast, smooth screw-in operation.Steel nuts assortment kit: includes steel nuts, which are coated with a coating to prevent corrosion and long-term use.Material: Carbon steelcolour: blackPackage Contents:1 box bolts and nuts (282pcs)Only the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.