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Suao is a professional manufacturer of high-precision cold drawn steel tubes, hydraulic tubes, and mechanical structure tubes, integrating R&D, production, inspection, and global sales. We operate two major production facilities covering over 36,000 square meters, with more than 200 employees and an annual output of 50,000+ tons, supplying customers across major industrial markets worldwide.
Our integrated manufacturing capabilities include cold drawing, heat treatment, straightening, finishing, cutting, chamfering, and surface treatment. These are supported by a full range of advanced equipment for non-destructive testing, chemical analysis, and online dimensional monitoring—ensuring every tube meets stringent quality standards.
We invest continuously in automation and smart manufacturing systems to enable flexible, high-mix, low-volume production. Our products are widely used in construction machinery, hydraulic systems, automotive parts, wind energy, shipbuilding, railways, and oil & gas sectors.
Certified to ISO 9001, ISO 14001, CE, and RoHS standards, Hongli is more than a manufacturer—we are a trusted long-term partner for global industrial clients.
Our ASTM A519 Hydraulic Cylinder Tubes are precision-manufactured using cold drawn seamless (CDS) steel pipes, ensuring superior mechanical strength, dimensional accuracy, and smooth inner surfaces.Produced in grades ST52, 27SiMn, and 20MnV6, these tubes are specially developed for hydraulic cylinder manufacturing, where high pressure, reliability, and excellent machinability are required.Compared with welded tubes, seamless tubes (ASTM A519) deliver higher strength, better fatigue resistance, and longer service life — making them the first choice for heavy-duty hydraulic applications.
