AISI4145H steel drill Non magnetic drill collar collar is a high strength, high hardness, resistance to twisting, bending, anti-wear special alloy steel, mainly for the G105,S135 drill pipe manufacturers manufacturing 1000-3000 meters deep underground working oil pump tubing outer sleeve in the domestic oil and gas industry are widely used. Since AISI4145H steel drill collars belonging to high-tech products with high added value, and with the continuous development of China's oil API Spec 5CT oil tubing pup joint in stock and gas industry, the market demand for larger, major steel companies are competing to seize the market, product competition is more intense.