Stainless Steel 13-8 PH
AISI/SAE 13-8 PH · UNS S13800 · ASTM XM-13 · EN 1.4534
13-8 PH (UNS S13800) is a low-carbon, vacuum-melted martensitic precipitation-hardening stainless steel strengthened by a NiAl phase formed from roughly 1% aluminium, with tightly controlled chemistry for a clean, isotropic structure.
Values for the Condition A condition
13-8 PH tempers and conditions
13-8 PH is supplied in 8 conditions, soft to hard. Condition A is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Double overaged 760 °C + 621 °C | Rarely stocked softest aged state used where maximum ductility, notch toughness and SCC immunity are required. | 725 | 900 | 22 | 28 HRC | 1.9 % IACS |
Condition ADefault solution annealed (~927 °C, air cooled) | As-supplied stock condition for machining, forming and welding before precipitation aging. | 827 | 1,000 | 13 | 33 HRC | — |
Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Maximum-toughness, best SCC-resistant temper; choose for corrosive service or heavy sections where 1035 MPa suffices. | 930 | 1,035 | 18 | 32 HRC | — |
Aged 593 °C (1100 °F) for 4 h | Overaged temper giving high toughness at ~1170 MPa UTS for thick, fracture-critical sections. | 1,070 | 1,170 | 16 | 35 HRC | — |
Aged 4 h at 566 °C (1050 °F), air cooled | Preferred when good SCC resistance and toughness matter more than the last 10 % of strength. | 1,210 | 1,310 | 15 | 40 HRC | — |
Aged 552 °C (1025 °F) for 4 h | Intermediate temper when slightly lower strength buys extra ductility and SCC margin over H1000. | 1,310 | 1,415 | 14 | 43 HRC | — |
Aged 4 h at 538 °C (1000 °F), air cooled | Most widely specified aerospace condition — near-peak strength with markedly better toughness than H950. | 1,415 | 1,520 | 13 | 45 HRC | — |
Aged 4 h at 510 °C (950 °F), air cooled | Peak-strength condition for maximum load capacity; least tolerant of corrosive or hydrogen-bearing environments. | 1,520 | 1,620 | 12 | 46 HRC | — |
What is 13-8 PH?
13-8 PH (UNS S13800) is a low-carbon, vacuum-melted martensitic precipitation-hardening stainless steel strengthened by a NiAl phase formed from roughly 1% aluminium, with tightly controlled chemistry for a clean, isotropic structure. Across the 1000–1600 MPa strength range it offers higher transverse toughness and fracture toughness than 17-4 PH with equal or slightly better corrosion resistance, and is used for landing gear parts, actuator rods, fasteners, mould inserts and high-strength shafts. Corrosion resistance is far below austenitic grades — not for long-term chloride immersion or hot H₂S service — the low-temperature H950 condition is sensitive to stress-corrosion cracking and hydrogen embrittlement, and machinability and cold formability are poor. 13-8 PH has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 58% of stainless steel grades. It melts at 1,400°C (2,552 °F). 13-8 PH has a yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 200 GPa (29 Msi).
What is 13-8 PH used for?
- Aircraft landing gear components
- Actuator rods and shafts
- Aerospace fasteners
- High-strength structural fittings
- Mould and die inserts
- Valve components
- Hydraulic and pump shafts
Advantages
- High strength — 827 MPa (120 ksi), better than 97% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
Limitations
- Limited ductility — 13%, worse than 93% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
13-8 PH properties
Typical room-temperature values for 13-8 PH-Condition A; bars are the position among stainless steel grades.
Physical3
13-8 PH has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 58% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
13-8 PH has a yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
13-8 PH is rated for continuous service to 425°C (797 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 10.6 µm/m·K (5.89 µin/in·°F).
Electrical3
13-8 PH conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of 13-8 PH takes about 62 MJ of energy and emits 5.2 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 30%.
Manufacturability8
13-8 PH's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability good (62/100); formability poor (28/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 13-8 PH is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 13-8 PH
Is 13-8 PH easy to machine?
Machine in Condition A with rigid setups, sharp carbide, positive rake and heavy coolant (~30 % of 1212); aged H950–H1000 work-hardens and needs reduced speeds and low feeds to avoid glazing.
Can 13-8 PH be welded?
Very good GTAW/EBW/laser weldability with matching or 13-8/15-5 filler, no preheat needed; weld in Condition A then re-solution + age (or age only) to restore joint strength.
Can 13-8 PH be formed, bent or molded?
Cold formability is limited even in Condition A — use generous bend radii; hot work 1040–1180 °C followed by solution anneal at ~927 °C and air cool.
Manufacturability
The process limits FabDigit applies to 13-8 PH. Every 13-8 PH part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair32 / 100 |
|---|---|
| ISO material group | M.3 |
| Cutting speed (rough / finish) | 120 / 140 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair28 / 100 |
|---|---|
| Weldability | Better62 / 100 |
13-8 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 |
|---|---|---|
| C | ≤ 0.05 | 0.03 |
| Mn | ≤ 0.2 | 0.05 |
| Si | ≤ 0.1 | 0.05 |
| P | ≤ 0.01 | 0.01 |
| S | ≤ 0.01 | 0 |
| Cr | 12.25 – 13.25 | 12.7 |
| Ni | 7.5 – 8.5 | 8 |
| Mo | 2 – 2.5 | 2.25 |
| AlNiAl precipitate former | 0.9 – 1.35 | 1.1 |
| N | ≤ 0.01 | 0.01 |
| Febalance, ~74–76 % | balance |
What surface finishes work on 13-8 PH?
Passivate per AMS 2700/ASTM A967 after machining; takes a fine polish and can be electropolished, shot-peened or thin-dense-chrome plated — bake after any plating to avoid hydrogen embrittlement.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 13-8 PH in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S13800
- ASTM
- XM-13
- EN / DIN / Werkstoff-Nr.
- 1.4534
How much does 13-8 PH cost?
13-8 PH is a specialty-cost stainless steel ($$$$$), pricier than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
13-8 PH — frequently asked
What is 13-8 PH used for?
13-8 PH is typically used for aircraft landing gear components, actuator rods and shafts, aerospace fasteners, high-strength structural fittings, mould and die inserts and valve components. In short: ultra-high strength stainless.
What is the yield strength of 13-8 PH?
13-8 PH has a typical yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 97% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 13-8 PH easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine in Condition A with rigid setups, sharp carbide, positive rake and heavy coolant (~30 % of 1212); aged H950–H1000 work-hardens and needs reduced speeds and low feeds to avoid glazing.
Can 13-8 PH be welded?
Yes — weldability is rated good (62/100). Very good GTAW/EBW/laser weldability with matching or 13-8/15-5 filler, no preheat needed; weld in Condition A then re-solution + age (or age only) to restore joint strength.
What surface finishes work on 13-8 PH?
Passivate per AMS 2700/ASTM A967 after machining; takes a fine polish and can be electropolished, shot-peened or thin-dense-chrome plated — bake after any plating to avoid hydrogen embrittlement.
Can 13-8 PH be formed, bent or molded?
Cold formability is limited even in Condition A — use generous bend radii; hot work 1040–1180 °C followed by solution anneal at ~927 °C and air cool.
What is the maximum service temperature of 13-8 PH?
13-8 PH is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 13-8 PH Condition A and 13-8 PH-H950?
Condition A is the default condition — as-supplied stock condition for machining, forming and welding before precipitation aging. H950: peak-strength condition for maximum load capacity; least tolerant of corrosive or hydrogen-bearing environments. Yield strength is 827 MPa in Condition A versus 1,520 MPa in H950.
How much does 13-8 PH cost?
13-8 PH is a specialty-cost stainless steel ($$$$$), pricier than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 13-8 PH?
Yes — 13-8 PH is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A564/A564M — Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars (Type XM-13) — ASTM International (2019)
- AMS 5629 / AMS 5934 — 13Cr-8Ni-2.2Mo-1.1Al bar, forgings and rings — SAE International (2018)
- EN 10088-3 / X3CrNiMoAl13-8-2 (1.4534) — CEN (2014)
- PH13-8Mo / 13-8 Stainless technical datasheet — Carpenter Technology / Cleveland-Cliffs (AK Steel) (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- MMPDS-2022 — Metallic Materials Properties Development and Standardization (PH13-8Mo) — Battelle/FAA (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.