SUS630)

17-4PH stainless steel, also known as AISI 630, UNS S17400, 1.4542, SUS630 and X5CrNiCuNb16-4, is a widely used martensitic precipitation-hardening stainless steel that combines high strength, excellent corrosion resistance, and good machinability and heat treatment performance. Through different aging conditions (such as H900 and H1025), it allows flexible adjustment of strength and toughness to meet the comprehensive performance requirements under various demanding service conditions, making it a highly versatile and broadly applied stainless steel.

ASTM F899：
Standard Specification for Wrought Stainless Steels for Surgical Instruments
ASTM A564：
Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes
AMS 5643 (SAE)：
Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings, 16Cr - 4.0Ni - 0.30Cb (Nb) - 4.0Cu, Solution Heat Treated, Precipitation Hardenable

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Chemical Composition

Element	C	Mn	P	S	Si	Cr	Ni	Cu	Nb+Ta	Fe
Content (%)	≤0.07	≤1.00	≤0.04	≤0.03	≤1.00	15.00-17.50	3.00-5.00	3.00-5.00	0.15-0.45	Balance

Heat Treatment Conditions and Mechanical Properties

Solution Treatment

Condition	Heating Temperature	Holding Time（h）	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation（4D）	Reduction of Area（%）	Hardness (HRC)
Solution Annealed	1900 ± 25 °F/1040±15℃	1	/	/	/	/	≤38

Aging Treatment

Condition	Heating Temperature	Holding Time（h）	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation（4D）	Reduction of Area（%）	Hardness (HRC)
Aged	900°F/480°C	1	≥1310	≥1170	10	40	≥40
Aged	925°F/495℃	4	≥1170	≥1070	10	44	≥38
Aged	1025°F/550°C	4	≥1070	≥1000	12	45	≥35
Aged	1100°F/595℃	1-4	≥965	≥795	14	45	≥32

Supply Forms

Available Form	Size Range	Surface Finish	Length (Customizable)	Tolerance (Customizable)	Delivery Condition
Plate	T0.5-T200.0mm	Milled / Bright	L:200/250/300 W:200/300/500/1000	-0.0/+1.0mm	Solution Annealed
Bar	φ1.0-φ200.0mm	Ground / Precision Polished	3M/PCS	h6-h9	Solution Annealed
Wire	φ1.0-φ3.0mm	Ground / Precision Polished	1M/PCS	h6-h9	Solution Annealed
Tube	OD：1.0-10.0mm ID:0.08mm-2.0mm	Ground / Precision Polished	3M/PCS	h6-h9	Solution Annealed

Datasheet

Additional Info

A Brief History of 17‑4 PH Stainless Steel

17-4 PH stainless steel, also known as UNS S17400, AISI 630, Type 630 or 1.4542, is a precipitation-hardening martensitic stainless steel primarily used in applications requiring high strength, good corrosion resistance and stable mechanical properties.

Since its introduction in the mid-20th century, 17-4 PH has become one of the most commonly used stainless steel grades in demanding engineering applications. Compared to conventional stainless steels, it offers a balance of good corrosion resistance and higher mechanical strength following age hardening.

Through its copper-based precipitation hardening mechanism, 17-4 PH achieves high tensile strength, good hardness and stable dimensional behaviour, whilst maintaining practical corrosion resistance in a variety of service environments. It is therefore suitable for components where strength, precision and durability are all required.

How 17‑4 PH Was Developed

17-4 PH stainless steel was developed to meet a specific material requirement: it must be capable of being machined or formed whilst remaining relatively easy to work with, whilst also achieving higher strength through controlled heat treatment. In the solution-annealed condition, commonly referred to as Condition A, the material can be machined or formed prior to final ageing treatment.

The alloy is designed based on a balance between chromium, nickel, copper and niobium. Chromium provides the corrosion resistance characteristic of stainless steel, nickel helps to improve toughness and microstructural stability, whilst copper and niobium support the precipitation hardening reaction during ageing.

Common age-hardened conditions include H900, H1025, H1075, H1100 and H1150. Different conditions offer varying combinations of strength, hardness, toughness and ductility, enabling engineers to select the most suitable heat-treated condition for the end application.

Early Applications of 17‑4PH

In its early applications, 17-4 PH stainless steel was quickly adopted by industries requiring high strength and a certain degree of corrosion resistance. Such applications typically demand material strength exceeding that of ordinary stainless steel, whilst offering better corrosion resistance than many alloy steels.

17-4 PH has been widely used in aerospace fasteners, shaft components, fasteners, valve components, structural parts and precision-machined parts. It is capable of achieving high strength through heat treatment whilst maintaining practical corrosion resistance, making it suitable for parts subjected to mechanical stress and moderate corrosive environments.

Another significant advantage is its relatively stable response to heat treatment. Manufacturers can achieve relatively consistent mechanical properties and dimensional stability, which is particularly important for precision parts requiring tight tolerances.

How 17‑4 PH Is Used Today

Today, 17-4 PH stainless steel is widely used in applications where strength, corrosion resistance, machinability and dimensional accuracy must work in concert.

Common areas of application include:

Medical: Surgical instruments, orthopaedic tools, medical device components and precision mechanical parts.

Aerospace: Structural fasteners, aircraft components, shaft components, fasteners and high-strength fasteners.

Mechanical engineering: Gears, pins, tooling components, wear-resistant parts and precision machined parts.

Industrial applications: Valve components, pump parts, high-strength fasteners, shaft components and structural components.

17-4 PH stainless steel is available in either a solution-annealed or age-hardened condition. Solution-annealed material is suitable for subsequent machining or further processing, whilst the age-hardened condition offers higher strength and hardness, making it suitable for load-bearing or wear-resistant applications.

For customers requiring better surface quality, dimensional consistency and reduced secondary processing, precision-ground bars and tight-tolerance products offer significant practical value.

Sunxin’s 17-4 PH stainless steel supply support

Sunxin manufactures and supplies 17-4 PH stainless steel in a variety of forms, including bars, plates, tubes, wire and custom precision-machined components. We can supply 17-4 PH stainless steel under common designations such as UNS S17400, AISI 630, Type 630, 1.4542, X5CrNiCuNb16-4 and SUS630.

Leveraging our expertise in material supply, engineering support and international trade, Sunxin provides material solutions for clients in the medical, aerospace, mechanical engineering and industrial sectors. Materials can be supplied in accordance with relevant standards and customer requirements, including ASTM, AMS, ISO, EN, DIN and other international specifications.

Sunxin prioritises consistent quality, reliable traceability, precise dimensions and flexible customisation. Whether you require 17-4 PH stainless steel bars for machining, plates for structural components, tubes for precision applications, or wire for specialised manufacturing, we can assist you in matching the appropriate material form, dimensions and delivery condition to your project requirements.

If you have requirements for 17-4 PH stainless steel, please contact Sunxin for supply support for projects requiring high-strength, corrosion-resistant materials.

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