Boya TCT Cutters offer an Advanced Tooth Geometry that Cuts, Cleans, and Clears while drilling, leading to Faster Holes and Longer Life. The cutters displace less material for the same size hole as the competition, giving you fast, burr-free holes in hard
Black carbon welded steel pipe means Electric Resistance Welded Pipes, mainly character is the welding beam is smooth, two end no burr, hardness is very strong, so some special material can be used for machine components.