~★Adapted to deep oil reservoir, hard stratum and severe earthiness, offsore oil and natural gas exploitation.    
★ Maximum and minimum service life more than 4000hours.    
★Phase transformation toughen technology has various advantages    
    Wear-resistance, Erosion-resistance    
    High-pressure-resistance, High- temperature-resistance    
    High strength and high hardness.    
★ Cost of shipment, Maintenance, labor and Storage in the drilling works reduced .    
★ Better toughness properties and longer service life.    
     Reduce piston wear and water consumption for lubrication.