Used for repairing damaged or stripped internal threads and creating a stronger internal thread. | Suitable for all metals, composites, polymers and other materials. Our thread repair kit can be widely used in automotive and plumbing applications. | 304 Stainless thread inserts create longer lasting durable threads, increase the possibility of higher torque application in weaker metals. 135° apex angle of twist drills, with stronger metal penetration and higher efficiency | Thread repair kit includes a collection of tools including HSS drill, tap, thread inserts, installation tool, break pin tool. | All the parts are organized in a convenient iron case for easy transport and storage between jobs. | Attention: Before you buy this kit, please make sure which size do you need. If you don't know, Please see the picture 6.