1. Hardness range of 285 to 341 BHN and a charpy impact value of 40ft/lbs are guaranteed for evenly distributed 16 points in any cross sections at room temperature.
2. Connections as phosphate coated father machining to protect the threads from corrosive elements and to prevent galling upon initial make -up. Thread roots are cold rolled on API and H0-90 connections.
3. Pressed steel thread protectors are supplied to all drill collar that are equipped with standard connections.
4. Manufactured strictly according to API standard.
5. Widely used in oil, gas, HDD and geothermal field.