Couplings and bit adaptors

　　known as coupling sleeves, used for connecting drill rods and shank adaptors, couplings, with the common threads of R38, T38, T45 and T51, include normal couplings and crossover couplings with full bridge or half bridge, and are widely used in open-pit mining, underground mining, tunneling, anchoring, furnace tapping, tunnel construction, hydropower projects, quarrying and construction.