... and timely delivery 3.20 years experience in drill equipment 1.Advantages of our products(1) strong resistance ... journal bearing)Aircooled bearing typeapplicationPetroleum and gas, water well, mining and tectonic industries, oil field, construction, geothermal, ... from basic cylindrical cutters to inserts with customized angles, diamond thickness, chamfers, and sizes.Hejian Wanda Petroleum Machinery ...