17-4pH Stainless Seamless Tube for High Strength Mechanical Fittings

• Customization: Available
• After-sales Service: Quality Objection Within 10 Days Since Receiving
• Warranty: 5 Years
• Model NO.: 17-4PH
• Type: Seamless
• Technique: Hot Rolled
• Material: Stainless Steel
• Usage: Pipeline Transport, Boiler Pipe, Hydraulic/Automobile Pipe, Oil/Gas Drilling, Food/Beverage/Dairy Products, Machinery Industry, Chemical Industry, Mining, Construction & Decoration, Special Purpose
• Section Shape: Round
• Diameter: 8-660mm
• Thickness: 1-150mm
• Length: as Required
• Steel Grade: 200 Series, 300 Series, Duplex, 904L 254smo
• Loading Port: Tianjin, Shanghai
• Place of Origin: Shandong, Jiangsu
• Stock: Normal Size in Stock, Special Size as Customized
• Delivery: Within 7 Days for Stock Cargo
• Packing: Standard Exporting Package
• Transport: by 20'gp or 40'gp
• Processing: as Customized (Cutting, Drilling.Ect)
• Mtc: Along with The Shipping Docs.
• Test: BV, SGS Is Available
• Stock Quantity: More Than 3000tons
• Payment: T/T, L/C
• Transport Package: Standard Exporting Package
• Specification: as required
• Trademark: Zengze
• Origin: Jiangsu
• HS Code: 7304499000
• Production Capacity: 5000tons Per Months

Product Description

Product Description

17-4PH is the most widely used precipitation hardening stainless steel grade, also named SUS630 or UNS S17400. It contains copper and niobium alloy elements, and forms nano precipitates after aging heat treatment to drastically boost mechanical strength, far superior to ordinary 304, 316L austenitic stainless steel. Under H900 aging condition, its tensile strength can reach up to 1310MPa, excellent for bearing heavy load, torsion, fatigue and impact force in harsh working conditions.
All products adopt hot piercing + cold drawn seamless forming process, completely weld-free structure with uniform wall thickness, compact internal metallographic structure and stable pressure resistance. Compared with welded tubes, seamless body eliminates hidden leakage and fatigue fracture risks for high-pressure mechanical fluid transmission and precision machined fittings. Its corrosion performance equals 304 stainless steel, resisting atmospheric oxidation, weak acid, water vapor and stress corrosion cracking, applicable to both indoor heavy machinery and offshore corrosive working environments.
The tube features good machinability and weldability. After solution annealing and customized aging treatment, it can be processed into valve bodies, shaft sleeves, threaded joints, hydraulic cylinder liners, pump core fittings and other precision mechanical parts through CNC turning, milling, drilling and tapping. Multiple aging states are optional: H900 for maximum hardness & strength, H1150 for better toughness and low-stress machining performance.
Each batch undergoes strict factory inspection, including PMI material verification, tensile & yield test, hardness test, hydraulic pressure test, eddy current and ultrasonic non-destructive flaw detection, with complete MTC test certificates for third-party quality audit. We provide fixed-length cutting, pipe end chamfering, surface pickling & passivation and bright annealing finishing to meet precision mechanical assembly requirements.

17-4PH (UNS S17400, SUS630) is precipitation hardening martensitic stainless steel seamless tube, manufactured per ASTM A564, AMS 5643 standards. It achieves ultra-high tensile strength and hardness via aging heat treatment, with balanced corrosion resistance similar to 304 stainless steel. Specially designed for high-strength mechanical fittings, high-pressure valve parts, hydraulic components, aerospace and oil & gas equipment. We support custom heat treatment (H900/H1025/H1150), precision machining, passivation and full non-destructive testing, with professional export packaging for high-end mechanical manufacturing projects.

Specification

ltem	parameter
Material Grade	17-4PH / UNS S17400 / SUS630 Precipitation Hardening Stainless Steel
Executive Standard	ASTM A564, AMS 5643, ASME SA564
Production Process	Hot Piercing + Cold Drawn Seamless
Outer Diameter Range	6mm – 219mm
Wall Thickness Range	0.5mm – 20mm
Standard Length	1m–6m, custom fixed-length cutting available
Heat Treatment State	Solution Annealed, H900 / H1025 / H1150 Aging
Surface Finish	Pickled Passivated / Bright Annealed
Inspection Items	PMI test, hardness test, tensile test, hydraulic test, UT & ECT non-destructive test
Available Processing	Cutting, chamfering, CNC machining, passivation, bright annealing
Core Application	High-strength mechanical fittings, valves, hydraulic parts, aerospace & oil equipment
MOQ	Negotiable, small sample trial order acceptable

Standard & Process 
Made per ASTM A564 via hot piercing and cold drawn seamless process. Multiple aging heat treatments (H900/H1025/H1150) adjust strength and toughness flexibly.
Outer Diameter 6mm–219mm
Small OD (6–30mm): Precision instrument tubing, tiny valve cores and sensor sleeves
Medium OD (30–100mm): Mainstream hydraulic cylinder, pump and general mechanical fittings
Large OD (100–219mm): Heavy-duty pressure vessels and large equipment structural parts

Wall Thickness 0.5mm–20mm
Thin wall (0.5–3mm): Light precision instrument and low-pressure fluid pipelines
Medium wall (3–10mm): Most common high-strength mechanical component base tubes
Thick wall (10–20mm): Ultra-high load, torsion and impact-resistant heavy fittings
Length & Surface 
Standard length 1–6m with custom cutting available. Pickled passivated or bright annealed surface improves anti-rust and wear performance.
 

Packaging & Shipping

Packing
Both tube ends fitted with dust-proof plastic caps to block impurities inside bore. Bundled with waterproof PE film, then loaded into solid export wooden crates to prevent bending and surface damage. Clear labels of grade, size, heat treatment state and shipping mark on each package.
Loading Port
Main ports: Tianjin Port, Shanghai Port. Support FCL, LCL and bulk shipment. Other designated ports can be arranged on request.

Shipping Method
Sea freight for bulk mechanical manufacturing orders; air freight or international express for small urgent sample testing. Accept customer's nominated freight forwarder.
Trade Terms
FOB, CFR, CIF, EXW are available. Export documents: Commercial Invoice, Packing List, Full Set B/L, ASTM Standard MTC Certificate.

Company Profile

Founded in 2007, Tianjin Zengze Steel has grown into a large-scale enterprise headquartered in Tianjin, home to North China's biggest man-made seaport. Leveraging Tianjin's superior transport accessibility, a mature global sales network, robust warehousing, processing and delivery infrastructure, as well as solid market credibility, the company has built a mutually beneficial cooperation bridge linking steel manufacturers and end buyers.
The firm's office sits at Xinduhui Square in Tianjin's Beichen District. It operates two independent steel processing bases within Tianjin TEDA Industrial Zone: one dedicated to hot-rolled steel and another for cold-rolled steel. The total land area of these two facilities exceeds 113,220 square meters, with a 70,000-metric-ton warehousing capacity and an overall annual processing output reaching 1 million metric tons.
Zengze Steel stepped into international trade in 2010 after securing its self-operated import and export qualification. Since then, it has delivered standardized global processing and logistics distribution services to clients across the globe. 
We strive to develop into an all-round service hub integrating steel processing, sorting and warehousing. We also aim to lead the steel industrial chain by pioneering innovative cost optimization schemes and advanced service philosophies.

Our Advantages

1.Standard 17-4PH precipitation hardening alloy with customizable aging treatment for target strength
2.Precision cold drawn seamless structure, high pressure tightness for high-strength mechanical fittings
3.Combined high hardness, fatigue resistance and moderate anti-corrosion performance
4.Complete CNC machining support for finished mechanical component production
5.Full non-destructive testing and official test certificates for industrial quality acceptance
6.Wide OD & wall thickness range covering various precision machinery design demands

6.Wide OD & wall thickness range covering various precision machinery design demands
7.Strict dimensional tolerance control to ensure accurate assembly of finished parts
8.Anti-collision wooden case packaging to protect high-value alloy tubes during ocean transport
9.Stable production capacity, flexible MOQ and competitive factory direct price for mechanical industry clients

FAQ

1.What does 17-4PH stand for? 
It is precipitation hardening martensitic stainless steel (SUS630/UNS S17400), gaining ultra-high strength through aging heat treatment.
2.What is the difference between H900 and H1150 treatment? 
H900 delivers maximum hardness and tensile strength; H1150 offers better toughness for easy post-processing machining.
3.Are these fully seamless tubes? 
Yes, all are seamless cold drawn tubes without welding seam, ideal for high-pressure mechanical applications.
4.Can you do customized aging heat treatment? 
We provide full aging condition customization according to customers' mechanical performance requirements.
5.What inspections are carried out before delivery? 
PMI material identification, hardness test, hydraulic bursting test, ultrasonic and eddy current flaw detection are fully implemented.
6.Is 17-4PH easy for CNC machining? 
Solution-annealed base material has great machinability for turning, drilling and complex fitting fabrication.
7.Does it have corrosion resistance? 
Corrosion resistance is comparable to 304 stainless steel, resisting moisture and weak corrosive medium erosion.
8.Can we customize non-standard sizes and fixed lengths? 
Custom outer diameter, wall thickness and arbitrary fixed-length cutting are fully supported.
9.What certificates can you provide? 
Formal MTC mill test reports complying with ASTM standards for third-party inspection and project filing.
10.How about export packaging for high-alloy tubes? 
Packed in sealed wooden cases with plastic end caps to avoid collision, scratch and oxidation in long-distance shipping.