Manufacturing Special Grade Steel Products: Founded in 1997, Zhejiang Guanyu Steel Tube CO., Ltd. specializes in stainless steel seamless tubes and pipes. Our Grades are 300 series especial in special grades including Duplex Steel (S31803 and 2205 ), 317L, 347H, 904L , and our main products include stainless and carbon steel pipe fittings, flanges and valves which are often used in the chemical and petrochemical industry, ship building, and fabrication of boiler & heat exchanger. Detailed Information and Main Markets of Our Products The O.D. of seamless pipe & tube is from 3mm to 630mm. And Thickness is from 0.2mm to 50mm. Our products have exported to more than 30 countries and got good reputation. Our main markets include Europe, USA, Korea, Malaysia, and Russia and Middle East. Contact Us "Quality first; credibility important". We welcome customers to visit our company. We look forward to your cooperation for mutual development.