Steel 13-8Mo-A (Solution annealed)
Temper
UNS S13800 · ASTM 5629
Supply/stock condition for machining, forming or subsequent aging; not a final service condition.
Values for the A condition
Other 13-8Mo tempers and conditions
13-8Mo is listed in 10 conditions; see the grade overview at 13-8Mo.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Double overaged 760 °C + 621 °C | Maximum ductility/toughness and lowest hardness; used for sour-service and heavy-section forgings. | 655 | 896 | 21 | 30 HRC | 1.9 % IACS |
AThis page Solution annealed | Supply/stock condition for machining, forming or subsequent aging; not a final service condition. | 827 | 1,000 | 12 | 33 HRC | — |
L-PBF as-built | Green-state AM parts before solution + aging; use only for fit checks or low-duty hardware. | 870 | 1,100 | 10 | 34 HRC | 1.7 % IACS |
Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Highest-toughness single-step age; best SCC and impact behaviour of the standard tempers. | 896 | 1,034 | 19 | 34 HRC | — |
Aged 593 °C (1100 °F) for 4 h | Over-aged condition for tough, damage-tolerant parts around 1100 MPa UTS. | 1,034 | 1,138 | 17 | 37 HRC | 1.8 % IACS |
Solution treated + aged 566 °C / 4 h | Good compromise when higher toughness and chloride-SCC margin matter more than peak strength. | 1,207 | 1,276 | 15 | 42 HRC | — |
Aged 552 °C (1025 °F) for 4 h | Slightly softer than H1000 with improved impact toughness; common for actuator and shaft parts. | 1,276 | 1,345 | 14 | 43 HRC | — |
L-PBF + solution treat + H1000 age | Standard AM post-process route giving near-wrought H1000 properties (add HIP for fatigue-critical parts). | 1,330 | 1,420 | 12 | 45 HRC | 1.7 % IACS |
H1000Default Solution treated + aged 538 °C / 4 h | The default aerospace balance of ~1400 MPa strength with good toughness and SCC resistance. | 1,345 | 1,413 | 14 | 45 HRC | — |
Solution treated + aged 510 °C / 4 h | Pick for maximum strength and hardness (fasteners, pins, tooling) where toughness demand is moderate. | 1,413 | 1,520 | 13 | 47 HRC | — |
What is 13-8Mo-A?
13-8Mo-A is 13-8Mo in the A temper — supply/stock condition for machining, forming or subsequent aging; not a final service condition. 13-8Mo-A has a yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Elongation at break is 12% and the elastic modulus is 203 GPa (29.4 Msi). 13-8Mo-A has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,400°C (2,552 °F). H1000 is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- Good corrosion resistance — 52/100, better than 99% of steel grades
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- High strength — 827 MPa (120 ksi), better than 87% of steel grades
Limitations
- Low electrical conductivity — 1.7 % IACS, worse than 100% of steel grades
- Poor heat conductor — 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 99% of steel grades
- High embodied carbon — 5.4 kg CO₂/kg, worse than 97% of steel grades
- Difficult to machine — 32/100, worse than 87% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
13-8Mo-A properties
Typical room-temperature values for 13-8Mo-A; 11 are specific to this condition. Other listed values are 13-8Mo reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
13-8Mo-A has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
13-8Mo-A has a yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Elongation at break is 12% and the elastic modulus is 203 GPa (29.4 Msi).
Thermal6
13-8Mo-A 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 99% of steel grades. Thermal expansion is 10.6 µm/m·K (5.89 µin/in·°F).
Electrical3
13-8Mo-A conducts electricity at 1.7 % IACS, worse than 100% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), better than 99% of steel grades.
Sustainability4
Producing a kilogram of 13-8Mo-A takes about 80 MJ of energy and emits 5.4 kg of CO₂ — more than 98% of steel grades. Typical recycled content is 30%.
Manufacturability8
13-8Mo-A's machinability is poor (32/100, worse than 87% of steel grades); weldability good (65/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 13-8Mo-A
Is 13-8Mo easy to machine?
Machine in Condition A or H1150 where possible; in H950–H1000 use rigid setups, positive-rake carbide, 20–40 m/min and heavy flood coolant to avoid work hardening and glazing.
Can 13-8Mo be welded?
Readily GTAW/EBW/laser welded autogenously or with matching filler; keep interpass low, then re-solution treat and re-age for full-strength joints (weld-as-aged loses strength in the HAZ).
Can 13-8Mo be formed, bent or molded?
Cold form only in Condition A with generous radii; heavy forming should be followed by re-solution treatment. Hot work 1150–950 °C, then solution anneal ~927 °C and air cool.
What surface finishes work on 13-8Mo?
Passivate per AMS 2700/ASTM A967 after machining; electropolishes and mirror-polishes well. Avoid electroplating without post-plate hydrogen bake (190 °C, 23 h) at H950–H1000 strength levels.
13-8Mo 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 | — |
| S | ≤ 0.01 | — |
| Cr | 12.25 – 13.25 | 12.75 |
| Ni | 7.5 – 8.5 | 8 |
| Mo | 2 – 2.5 | 2.25 |
| Alprincipal precipitation hardener (NiAl) | 0.9 – 1.35 | 1.1 |
| N | ≤ 0.01 | — |
| Fe | balance | — |
13-8Mo-A — frequently asked
What is 13-8Mo-A used for?
13-8Mo-A is typically used for aerospace structural parts, fasteners and landing gear components. In short: tougher than 17-4PH; aerospace PH stainless; tunable H950–H1150 strength.
What is the yield strength of 13-8Mo-A?
13-8Mo-A has a typical yield strength of 827 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 13-8Mo-A easy to machine?
Not especially — machinability is rated poor (32/100, worse than 87% of steel grades). Machine in Condition A or H1150 where possible; in H950–H1000 use rigid setups, positive-rake carbide, 20–40 m/min and heavy flood coolant to avoid work hardening and glazing.
Can 13-8Mo-A be welded?
Yes — weldability is rated good (65/100). Readily GTAW/EBW/laser welded autogenously or with matching filler; keep interpass low, then re-solution treat and re-age for full-strength joints (weld-as-aged loses strength in the HAZ).
What surface finishes work on 13-8Mo-A?
Passivate per AMS 2700/ASTM A967 after machining; electropolishes and mirror-polishes well. Avoid electroplating without post-plate hydrogen bake (190 °C, 23 h) at H950–H1000 strength levels.
Can 13-8Mo-A be formed, bent or molded?
Cold form only in Condition A with generous radii; heavy forming should be followed by re-solution treatment. Hot work 1150–950 °C, then solution anneal ~927 °C and air cool.
What is the maximum service temperature of 13-8Mo-A?
13-8Mo-A 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 13-8Mo-H1000 and 13-8Mo-H1150M?
H1000 is the default condition — the default aerospace balance of ~1400 MPa strength with good toughness and SCC resistance. H1150M: maximum ductility/toughness and lowest hardness; used for sour-service and heavy-section forgings. Yield strength is 1,345 MPa in H1000 versus 655 MPa in H1150M.
Sources
- AMS 5629 — Steel Bars, Forgings, Rings, 13Cr-8Ni-2.2Mo-1.1Al, consumable electrode melted — SAE International (2018)
- ASTM A564/A564M — Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars (UNS S13800) — ASTM International (2019)
- PH13-8Mo Stainless Steel Technical Data Sheet — Carpenter Technology / AK Steel (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- MMPDS-17 — Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
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.