After heat it is highly durability, and is not easily worn Conquers compactly Spaces with Extended Reach Strong antislip head: Antislip head, strong bites, stable and nonslip thread; Strong firm adsorption and more efficient operate Straight and concentrics: Straight and concentrics, say goodbye to slipping, say goodbye to idling, high concentricity and improve work efficiency Upgrading Phosphate high hardness steel + phosphate overall antirust, Manufacturer: Zeizafa