With 35 years’ experience,USI is a Manufacturer and Exporter of Steel Pipe(carbon steel, stainless steel, alloy steel) and Pipe fittings. LSAW/SSAW/ERW Steel Pipe, Stainless Steel Pipe, Pipe fittings and valves, Tubing and Casing. Standard: API 5L PSL1 / PSL2 Gr.A, Gr.B, X42, X46, X52, X56, X60, X65, X70 ASTM A53 / A252 / A500 / A672 / A691 / A139 EN10025 / EN10210 / EN10219 / EN10217 / EN10208 / EN10297 AS1163 / JIS G3457 / JIS G3101 DIN 17100 Material: 300series:301,304,304L,,309,309S,310,310S,316,316L,321,347,347H; 400series:410,420,430,420J2,439,409,430S,444,431,441,446,440A,440B,440C. Duplex:S31803, S32250, S32750, S32760, S31500, 32001. S32003, S32304. Nickele bass alloy: N08800,N08810,N08811,N08825,N06625 Other special: S31254,N08367,N08904