17-4PH (UNS S17400) is a chromium-nickel-copper precipitation-hardening martensitic stainless steel, further strengthened by a niobium addition. What makes this alloy unique is its ability to be heat treated after fabrication through a simple aging process, transforming it from a workable, moderately hard material into a high-performance engineering grade with strength levels far exceeding conventional austenitic stainless steels. Depending on the aging condition selected — from H900 through to H1150 — tensile strengths ranging from approximately 930 MPa to 1310 MPa can be achieved, while maintaining corrosion resistance broadly comparable to AISI 304 stainless steel.
Stainless Steel dealers in UAE
17-4PH
Precipitation-hardening martensitic stainless steel combining high strength and good corrosion resistance — properties fully tailored through aging heat treatment from H900 to H1150.
Industries Served
Oil & Gas
Aerospace & Defense
Marine
Petrochemical
Nuclear
Medical
Manufacturing
Power Generation
Food Processing
Applications
- Aerospace components: aircraft fittings, fasteners, and landing gear structural parts
- Oil & gas valve stems, pump shafts, and wellhead components
- Marine hardware, offshore structural components, and subsea connectors
- Chemical processing pump parts, agitators, and mixer shafts
- Nuclear waste handling equipment and pressure vessel components
- High-strength fasteners, bolts, and gears for critical applications
- Turbine blades and jet engine compressor components
- Medical surgical instruments and orthopedic implant components
- Food processing machinery requiring both strength and hygiene
- Pulp and paper processing equipment
Chemical Composition
0.04 %
CCarbon
≤ 0.07 %
0.6 %
MnManganese
≤ 1 %
0.5 %
SiSilicon
≤ 1 %
P
Phosphorus
≤ 0.04 %
S
Sulfur
≤ 0.03 %
16.3 %
CrChromium
15 – 17.5 %
4.2 %
NiNickel
3 – 5 %
3.5 %
CuCopper
3 – 5 %
0.3 %
Nb + TaNiobium+Tantalum
0.15 – 0.45 %
Mo
Molybdenum
≤ 0.5 %
Typical value Range (min–max) Minimum (≥) Maximum (≤) Hover / tap for notes
Standard
A564/A564M — 2023
Available Forms
Round Bar
Solid circular cross-section. Most common supply form for 17-4PH.
Flat Bar
Rectangular cross-section bar.
Plate
Flat product thickness typically >6mm. Per ASTM A693.
Sheet
Flat product thickness typically ≤6mm. Per ASTM A693.
Forging
Open or closed die forged product. Per ASTM A705.
Ring Forging
Rolled ring forging for flanges and circular components.
Designations & Equivalents
| Standard | Designation | Notes |
|---|---|---|
| UNS | S17400 | Unified Numbering System — primary identifier |
| AISI / Type | Type 630 | AISI type designation — also written AISI 630 |
| EN / Werkstoff | 1.4542 | European material number |
| EN Name | X5CrNiCuNb16-4 | Full EN chemical composition designation |
| AMS | AMS 5643 | Aerospace bar/forging spec. AMS 5604 for sheet/plate. |
| ASTM | A564 Type 630 | Bar standard. Also: A693 (sheet/plate), A705 (forgings) |
| ASME | SA564 | ASME pressure equipment equivalent of ASTM A564 |
| Common Name | 17-4PH, 17/4, SS 630 | Trade and common names used in industry |
Compliance & Certification
| Standard | Status | Notes |
|---|---|---|
| EN 10204 3.1 | Suitable | Mill Test Certificate provided as standard with all Nifty Alloys supply. |
| EN 10204 3.2 | Conditional | Available on request — third-party inspection required at order stage. |
| NACE MR0175 / ISO 15156 | Requires Confirmation | H1025 may comply depending on actual hardness. Confirm hardness ≤ project NACE limit. H1150 provides greater confidence for sour service. |
| NACE MR0103 | Requires Confirmation | As above — confirm hardness compliance per project specification. |
| AMS 5643 | Suitable | Commonly supplied to AMS 5643 — confirm at order stage. |
| ASME SA564 | Suitable | For pressure vessel applications — confirm applicable ASME code edition. |
Specifications
Mechanical Properties
Values are minimums unless noted; hardness is a maximum.
| Property | 17-4PH — ASTM A564 — H1025Default | 17-4PH — ASTM A564 — H900 | 17-4PH (1.4542) — EN 10088-3 — Solution Annealed (+AT) |
|---|---|---|---|
| Tensile Strength (UTS)min | 1070 MPaTypical: 1170 MPaCondition: Room temp (+20°C), longitudinalNotes: Minimum per ASTM A564 H1025. | 1310 MPaTypical: 1380 MPaCondition: Room temp (+20°C), longitudinalNotes: HIGHER than H1025. Min per ASTM A564 H900. | — |
| Yield Strength (0.2% Proof Stress)min | 1000 MPaTypical: 1070 MPaCondition: Room temp, longitudinalNotes: Minimum per ASTM A564 H1025. | 1170 MPaTypical: 1240 MPaCondition: Room temp, longitudinalNotes: HIGHER than H1025. Min per ASTM A564 H900. | — |
| Elongationmin | 12 %Typical: 16 %Condition: 50mm gauge length, longitudinalNotes: Minimum per ASTM — better ductility than H900. | 10 %Typical: 14 %Condition: 50mm gauge length, longitudinalNotes: LOWER than H1025 — less ductile. | — |
| Reduction of Areamin | 45 %Typical: 55 %Condition: LongitudinalNotes: Minimum per ASTM — improved vs H900. | 40 %Typical: 50 %Condition: LongitudinalNotes: LOWER than H1025. | — |
| Hardnessmax | 35 HRCTypical: 33 HRCCondition: Surface, Rockwell C scaleNotes: Maximum per ASTM. Approx 352 HB. | 40 HRCTypical: 38 HRCCondition: Surface, Rockwell C scaleNotes: HIGHER than H1025 (max 40 vs 35). Approx 375 HB. | — |
| Impact Energy (Charpy V-notch)typical | 35–50 JCondition: Room temp (+20°C), V-notchNotes: Typical — more than double H900 toughness. | 15–20 JCondition: Room temp (+20°C), V-notchNotes: LOWEST toughness of all conditions. Approx half of H1025. | — |
| Hardness (+AT delivery condition)max | — | — | 363 HBTypical: 300 HBCondition: Brinell — +AT delivery stateNotes: Max hardness in solution annealed condition — for machinability and formability. |
| Tensile Strength (after aging)min | — | — | 1070 MPaTypical: 1170 MPaCondition: After standard aging per ENNotes: Equivalent to H1025 range after precipitation hardening. |
| Yield Strength (after aging)min | — | — | 1000 MPaTypical: 1070 MPaCondition: After aging per ENNotes: Minimum after aging. |
| Elongation (after aging)min | — | — | 10 %Typical: 14 %Condition: 50mm gauge, longitudinalNotes: Minimum after aging per EN 10088-3. |
Physical Properties
| Property | 17-4PH — ASTM A564 — H1025Default | 17-4PH — ASTM A564 — H900 | 17-4PH (1.4542) — EN 10088-3 — Solution Annealed (+AT) |
|---|---|---|---|
| Density20°C | 7.82 g/cm³ | 7.82 g/cm³ | — |
| Modulus of Elasticity25°C | 197 GPa | 197 GPa | — |
| Thermal Conductivity20°C | 18.4 W/m·K | 18.4 W/m·K | — |
| Coefficient of Thermal Expansion20–260°C range | 10.8 µm/m·°C | 10.8 µm/m·°C | — |
| Specific Heat Capacity20°C | 460 J/kg·K | 460 J/kg·K | — |
| Melting RangeSolidus | 1404 °C | 1404 °C | — |
ENGINEERING NOTES
Weldability
Good17-4PH can be welded using standard TIG/MIG methods without preheat in most cases. Weld in Condition A for best results. Post-weld solution annealing then aging is recommended to restore full corrosion resistance and mechanical properties.
Machinability
GoodMachines well in Condition A and all aged conditions. Carbide tooling is strongly preferred. H900 is most demanding due to high hardness. Overaged conditions (H1150, H1150M) offer 30–50% better machinability than H900. Allow for slight dimensional change if post-machining aging is required.
Nifty Alloys supplies 17-4PH in round bar, flat bar, plate, and forgings in Condition A (solution annealed) and H1025 from stock, with other conditions available on request. All material is supplied with EN 10204 3.1 Mill Test Certificates as standard, and EN 10204 3.2 third-party inspection is available for critical project requirements. Our team has the expertise to advise on the correct aging condition for your specific application — whether you are sourcing for aerospace fasteners, oil and gas valve components, marine hardware, or precision machined parts. With stock availability across the UAE and GCC, and a commitment to certified, traceable supply, Nifty Alloys is your trusted partner for 17-4PH in the region.
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Contact our team17-4PH is available in Condition A, H900, H925, H1025, H1075, H1100, H1150, and H1150M. Nifty Alloys commonly stocks Condition A and H1025. Specify the required condition clearly when ordering.
Ras Al Khor Ind. Area-2, Dubai United Arab Emirtates
+971 565450916
