630 is Cu-Nb precipitation hardening martensitic stainless steel bright bar, the most widely used PH grade.

Strengthening mechanism: Solution water quenching at 1020~1050℃ delivers soft martensite matrix; low-temperature aging precipitates Cu intermetallic phases & NbC for dispersion hardening. Minimal component distortion due to low-temperature aging, multiple aging grades H900/H1025/H1075/H1150/H1100M with adjustable hardness HRC28~48, balanced high strength & toughness.

Niobium binds free carbon to eliminate intergranular corrosion at 425~850℃ after welding & long-term heating. High Cr-Cu matrix provides superior resistance to atmosphere, fresh water, mild brine and weak acid vs standard martensitic 410/420/431, slightly inferior to 316L & 904L. Ultra-low carbon ensures good weldability, strength restored by post-weld aging without full re-solution treatment.

Chemical element content (%)

Specification：1.00~300.00mm

Application:It is mainly used to manufacture aerospace hydraulic valve stems, low-pressure chloride fasteners for oil & gas industry, medium-temperature heat exchange load-bearing shafts for solar thermal power stations, mild bleaching wear pins for food processing, non-MRI anti-corrosion medical connectors, low-temperature desulfurization valve bodies for waste incineration, high-pressure circulating cooling water standard parts, mass pins & shafts processed by Swiss CNC lathes, internal wear-resistant bars for general hydraulic equipment, fresh water chemical reactor flanges, etc.
Widely applied in aerospace precision components, petrochemical low-pressure mild chloride units, solar thermal heat exchange equipment, food anti-corrosion wear-resistant production lines, civil circulating water facilities, medical anti-corrosion hardware, complete low-temperature waste heat desulfurization plants and general precision hydraulic machinery industries.

Core Advantages Over Competitors

1. High quality stability: Full closed-loop production with dual online spectral & metallographic inspection strictly control C, Cr, Ni, Cu, Nb with evenly dispersed Cu-Nb precipitates. Consistent hardness range for all aging grades ensures negligible batch fluctuation of dimensional stability and mechanical properties for mass production of aerospace & hydraulic precision components.

2. Excellent surface quality: High-precision cold drawing & centerless grinding lines produce smooth bars free of scale, scratches and pits. Minimal dimensional shift after low-temperature aging, no secondary polishing required for most precision appearance requirements.

3. Ultra-high dimensional accuracy: Precision rolling mills & automatic online detectors narrow tolerance range with tiny single-bar deviation and high batch uniformity, unifying component sizes during automatic mass production to extend finished yield.

4. Rich product variety: According to market demand and customer's special requirements, customized products are provided to meet the use requirements under various complex working conditions, providing customers with more choices.

5. Perfect after-sales service: The perfect after-sales service system can respond to customer needs and feedback in a timely manner. For problems encountered by customers during use, technical support and solutions are provided to customers quickly.

We mainly engage in cold heading wire, bar, peeled bar, and profiled bar; our products cover 11 series and more than 300 grades, and we continue to develop a variety of professional steels. We can provide all-round solutions such as cold heading finishing line manufacturing and high-precision bright bar customization, and provide one-stop procurement services and package procurement solutions for global customers. The website displays some grades. If you don’t have the grade you need, please contact us by phone or email.