Stainless Steel 17-4 PH · precip hard
Stainless Steel 17-4 PH-H900
Properties of the H900 condition, compared with the other 17-4 PH tempers.
Pick for maximum strength and hardness where toughness and SCC resistance are secondary.
What is 17-4 PH-H900?
17-4 PH-H900 is 17-4 PH in the H900 condition — pick for maximum strength and hardness where toughness and SCC resistance are secondary. 17-4 PH-H900 has a yield strength of 1,275 MPa (185 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 196 GPa (28.4 Msi). 17-4 PH-H900 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,404°C (2,559 °F). Condition A is the default condition FabDigit quotes; H900 is available on request or by drawing note.
Advantages
- High strength — 1,275 MPa (185 ksi), better than 99% of stainless steel grades
Limitations
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 94% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Needs corrosion protection — 50/100, worse than 79% of stainless steel grades
17-4 PH-H900 properties
Typical room-temperature values for 17-4 PH-H900 — 18 properties are specific to this condition; the rest are grade-level values shared by every 17-4 PH temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
17-4 PH-H900 has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 57% of stainless steel grades. It melts at 1,404°C (2,559 °F).
Mechanical16
17-4 PH-H900 has a yield strength of 1,275 MPa (185 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
17-4 PH-H900 is rated for continuous service to 300°C (572 °F). It conducts heat at 18.3 W/m·K (10.6 BTU/hr·ft·°F), better than 74% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
17-4 PH-H900 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 79% of stainless steel grades.
Sustainability4
Producing a kilogram of 17-4 PH-H900 takes about 55 MJ of energy and emits 5.2 kg of CO₂ — less than 51% of stainless steel grades. Typical recycled content is 50%.
Manufacturability8
17-4 PH-H900's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (70/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 17-4 PH tempers and conditions
17-4 PH is also supplied in 17 other conditions. The full side-by-side table is on the 17-4 PH overview.
- Condition ADefaultStandard stock condition — machine in this state, then age to the required H-temper.760 MPa yield · 33 HRC
- H900Pick for maximum strength and hardness where toughness and SCC resistance are secondary.1,275 MPa yield · 44 HRC
- P1300Peak-aged European condition equivalent to H900 (≈480 °C / 1 h): Rm ≥ 1300 MPa and ~42 HRC, the highest strength and hardness available in 1.4542 bar.1,220 MPa yield · 42 HRC
- H925Slight ductility/SCC gain over H900 with only a small strength penalty.1,170 MPa yield · 42 HRC
- H1025Balanced strength/toughness for shafts and highly loaded machined parts.1,070 MPa yield · 38 HRC
- P1070European aged condition equivalent to about H1025: Rm 1070–1270 MPa with 0.2 % proof stress ≥ 1000 MPa, a common balance of strength and toughness for shafts and valve parts.1,060 MPa yield · 36 HRC
- H1075Good general-purpose temper when notch toughness matters more than peak strength.1,000 MPa yield · 36 HRC
- H1100Higher toughness / lower hardness temper for impact-loaded or moderately corrosive service.900 MPa yield · 33 HRC
- H1150Maximum toughness and best SCC resistance of the single-age tempers; common for subsea/valve parts.800 MPa yield · 31 HRC
- P900Intermediate European aged condition (≈580–600 °C age, between H1100 and H1150) with Rm 900–1050 MPa and still good ductility and impact energy.790 MPa yield · 31 HRC
- HIPCloses AM/casting porosity for fatigue-critical parts; follow with the required H-temper aging.780 MPa yield · 32 HRC
- H1150DSpecified for sour-service oilfield hardware where hardness must stay at or below 33 HRC per NACE MR0175.730 MPa yield · 30 HRC
- P800European over-aged PH condition (≈480–620 °C long age, close to H1150): lowest strength but highest toughness and best stress-corrosion behaviour, Rm 800–950 MPa.660 MPa yield · 28 HRC
- As PrintedBaseline for AM parts; anisotropic, contains retained austenite and residual stress — normally re-solutioned and aged.650 MPa yield · 30 HRC
- H1150MLowest-strength, highest-ductility condition for maximum notch toughness and cryogenic/sour service.620 MPa yield · 26 HRC
Working with 17-4 PH-H900
Is 17-4 PH easy to machine?
Machine in Condition A or H1150 with rigid setups, positive-rake carbide, 60–110 m/min and heavy feeds; work hardens readily, so avoid dwelling — allow ~0.05 % shrinkage on aging (H900 grows/shrinks slightly).
Can 17-4 PH be welded?
Very good weldability by GTAW/GMAW/laser with matching 17-4 or ER630 filler, no preheat required; re-solution + age (or at minimum a direct H1150 age) after welding to restore properties.
Can 17-4 PH be formed, bent or molded?
Cold forming is limited in Condition A (bend radii ≥ 2t); hot work 1150–1200 °C and finish above 950 °C, then solution treat — for AM use 20–50 µm gas-atomized powder with N₂-free atmosphere to control retained austenite.
What surface finishes work on 17-4 PH?
Passivate per ASTM A967 (citric or nitric) after machining; takes a high polish for mold inserts and accepts hard chrome, electroless nickel or PVD — never anodized.
17-4 PH chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CASTM A564 Type 630 | ≤ 0.07 | 0.04 |
| Mn | ≤ 1 | 0.5 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 15 – 17.5 | 16 |
| Ni | 3 – 5 | 4.2 |
| Cu | 3 – 5 | 3.8 |
| Nb+TaCb+Ta stabilizer, drives NbC/Cu precipitation | 0.15 – 0.45 | 0.3 |
| Fe | balance | — |
17-4 PH-H900 — frequently asked
What is 17-4 PH-H900 used for?
17-4 PH-H900 is typically used for pump shafts, valve stems and internals, aerospace structural fittings, injection mould inserts, high-strength fasteners and additively manufactured brackets and manifolds. In short: standard aerospace PH.
What is the yield strength of 17-4 PH-H900?
17-4 PH-H900 has a typical yield strength of 1,275 MPa (185 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 99% of stainless steel grades. Strength varies by condition: see the 18 listed tempers.
Is 17-4 PH-H900 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine in Condition A or H1150 with rigid setups, positive-rake carbide, 60–110 m/min and heavy feeds; work hardens readily, so avoid dwelling — allow ~0.05 % shrinkage on aging (H900 grows/shrinks slightly).
Can 17-4 PH-H900 be welded?
Yes — weldability is rated very good (70/100). Very good weldability by GTAW/GMAW/laser with matching 17-4 or ER630 filler, no preheat required; re-solution + age (or at minimum a direct H1150 age) after welding to restore properties.
What surface finishes work on 17-4 PH-H900?
Passivate per ASTM A967 (citric or nitric) after machining; takes a high polish for mold inserts and accepts hard chrome, electroless nickel or PVD — never anodized.
Can 17-4 PH-H900 be formed, bent or molded?
Cold forming is limited in Condition A (bend radii ≥ 2t); hot work 1150–1200 °C and finish above 950 °C, then solution treat — for AM use 20–50 µm gas-atomized powder with N₂-free atmosphere to control retained austenite.
What is the maximum service temperature of 17-4 PH-H900?
17-4 PH-H900 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 17-4 PH Condition A and 17-4 PH-CH900?
Condition A is the default condition — standard stock condition — machine in this state, then age to the required H-temper. CH900: strip/foil condition for springs and diaphragms needing the highest attainable strength. Yield strength is 760 MPa in Condition A versus 1,350 MPa in CH900.
Can FabDigit make parts in 17-4 PH-H900?
Yes — 17-4 PH-H900 is available for CNC machining, sheet metal, 3D printing and casting & forging with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A564/A564M — Age-Hardening Stainless Bars and Shapes (Type 630) — ASTM (2019)
- AMS 5643 — Steel, Corrosion and Heat-Resistant, Bars, Wire, Forgings (17-4 PH) — SAE International (2020)
- EN 10088-3 / X5CrNiCuNb16-4 (1.4542) — CEN (2014)
- GB/T 1220 (05Cr17Ni4Cu4Nb) — SAC (2007)
- 17-4 PH Stainless Steel Product Data Bulletin — AK Steel / Cleveland-Cliffs (2016)
- ATI 17-4 Precipitation Hardening Stainless Steel Technical Data Sheet — ATI (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- NACE MR0175/ISO 15156-3 — hardness limits for UNS S17400 — NACE/ISO (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.