Roc-Master Flange Co., Ltd. is located in Minhang heavy-industry District of Shanghai. This plant is specialized in providing sales services and technical support .we do machining, drilling, cladding and welding in Shanghai. Meanwhile Roc-Master Shanghai is considered to be our inspection and logistics service center。 We are ISO 9001:2000 accredited since 2002. We obtained API 17D license in 2007. Quality control is performed from the chemical analysis of raw-material, manufacturing to heat-treatment, to finishes process, every step of the manufacturing process. We have an air hammers for producing high performance forged bolts & nuts up to 4 inch. We have a 4-Ton electro-hydraulic hammer manipulator operating flange production, and the maximum outside diameter is up to 1600mm, maximum gross weight up to 4 tons. Our annual production capacity of Flange is 3000tons; We have an automatic cladding machine in Shanghai. Flange cladding diameter range is from 6 to1170mm, the height rang from 0 to 406mm. We do a whole set of chemical and mechanical performance test, metallurgical structure , hardness test, NDE test, salt-fog test, film thickness test, roughness test, and the lowest temperature of impact test can be -196 degree C. We treat Quality, Customer, Market, Upgrade as the most important .