dear sirs, Guiyang steel mills is one of the key special steel manufacturer in china, rank one of the 500 largest enterprise in China.  Guiyang steel mills is also one of the largest rock drilling tools producer in ASIA AREA. our exporting items include: --alloy steel bars(round and hexagon ) tool steel, mould steel, bearing steel ,free cut steel, carbon steel,forging die. and etc. such as H11,H13,H21,P20, S1,S5,S7,4140,4340,8620, and etc. --rock driling tools hollow steel bars, drilling rod. button bit taper rod,  integral drill rod, shank adaptor, coupling , and etc. especailly our hollow steel bars ,which have good price and quality, and it is our main exporting items. --Bright steel rod and mould components : Include silver steel round rods, ejector sleeves, straight leader pins, shoulder leader pins, dowel pin, shoulder bushing, hotwork ejector pins , stepped ejector pi