Steel 16Mo3-A (Solution annealed)
Temper
EN 16Mo3
Softest condition for deep cold forming, heavy machining or cold-drawn tube intermediate stage.
Values for the A condition
Other 16Mo3 tempers and conditions
16Mo3 is listed in 7 conditions; see the grade overview at 16Mo3.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Softest condition for deep cold forming, heavy machining or cold-drawn tube intermediate stage. | 265 | 450 | 30 | 135 HB | 7.9 % IACS |
Stress relieved | Ordered when the vessel will see post-weld heat treatment; properties are certified after the simulated PWHT cycle (~620–680 °C). | 295 | 470 | 27 | 145 HB | 7.8 % IACS |
normalized and tempered | Used for heavy plate and forgings where tempering after normalizing improves toughness uniformity through thickness. | 300 | 475 | 27 | 145 HB | 7.8 % IACS |
NDefault Normalized | Standard stocked condition for boiler plate, tube and pipe; fine-grained ferrite-pearlite with guaranteed elevated-temperature proof stress. | 310 | 490 | 26 | 150 HB | 7.8 % IACS |
as-rolled (hot rolled, no subsequent heat treatment) | Economy condition for thin plate/strip where normalizing is not required by the code; properties vary more with thickness. | 315 | 500 | 24 | 155 HB | 7.8 % IACS |
Quenched and tempered | Chosen for thick forgings and flanges (EN 10222-2) needing higher yield strength and low-temperature toughness. | 400 | 560 | 22 | 178 HB | 7.6 % IACS |
cold drawn (seamless tube / bar, as-drawn) | Cold-drawn tube or bar for tight tolerance and higher strength; must be normalized before use above design creep temperatures. | 450 | 560 | 13 | 175 HB | 7.8 % IACS |
What is 16Mo3-A?
16Mo3-A is 16Mo3 in the A temper — softest condition for deep cold forming, heavy machining or cold-drawn tube intermediate stage. 16Mo3-A has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 30% and the elastic modulus is 212 GPa (30.7 Msi). 16Mo3-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). N is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Easy to machine — 64/100, better than 92% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Forms and bends easily — 75/100, better than 90% of steel grades
- High service temperature — 450°C (842 °F), better than 86% of steel grades
Limitations
- Low strength — 265 MPa (38.4 ksi), worse than 92% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
16Mo3-A properties
Typical room-temperature values for 16Mo3-A; 22 are specific to this condition. Other listed values are 16Mo3 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
16Mo3-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
16Mo3-A has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 30% and the elastic modulus is 212 GPa (30.7 Msi).
Thermal6
16Mo3-A is rated for continuous service to 450°C (842 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
16Mo3-A conducts electricity at 7.9 % IACS, better than 50% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 16Mo3-A takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
16Mo3-A's machinability is good (64/100, better than 92% of steel grades); weldability very good (82/100); formability very good (75/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 16Mo3-A
Is 16Mo3 easy to machine?
Machines like a medium-carbon steel — carbide tooling, ~120–180 m/min turning speed in the normalized state; Mo gives slightly gummier chips than plain C-Mn steel.
Can 16Mo3 be welded?
Good weldability with SMAW/SAW/GTAW using matching 1%Mo consumables (E7018-A1, ER80S-G); preheat 100–200 °C for t > 20 mm and PWHT at 620–680 °C to restore HAZ toughness.
Can 16Mo3 be formed, bent or molded?
Hot form at 900–1050 °C followed by re-normalizing; cold bending is practical to about 3t radius in annealed or normalized plate.
What surface finishes work on 16Mo3?
No anodizing; protect by shot blasting plus epoxy/high-temperature silicone paint, aluminizing or thermal insulation, and control corrosion under insulation.
16Mo3 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 | 0.12 – 0.2 | 0.16 |
| Si | ≤ 0.35 | 0.25 |
| Mn | 0.4 – 0.9 | 0.65 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.01 | 0.01 |
| Mocreep-strengthening addition | 0.25 – 0.35 | 0.3 |
| Crresidual | ≤ 0.3 | 0.1 |
| Niresidual | ≤ 0.3 | 0.1 |
| Curesidual | ≤ 0.3 | 0.1 |
| Nb | ≤ 0.01 | — |
| Ti | ≤ 0.03 | — |
| Fe | balance | — |
16Mo3-A — frequently asked
What is 16Mo3-A used for?
16Mo3-A is typically used for boiler tubes, pressure vessels, piping and heat exchangers. In short: baseline C-Mo boiler steel; best weldability in family; service to about 450 °C.
What is the yield strength of 16Mo3-A?
16Mo3-A has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 16Mo3-A easy to machine?
Reasonably — machinability is rated good (64/100, better than 92% of steel grades). Machines like a medium-carbon steel — carbide tooling, ~120–180 m/min turning speed in the normalized state; Mo gives slightly gummier chips than plain C-Mn steel.
Can 16Mo3-A be welded?
Yes — weldability is rated very good (82/100). Good weldability with SMAW/SAW/GTAW using matching 1%Mo consumables (E7018-A1, ER80S-G); preheat 100–200 °C for t > 20 mm and PWHT at 620–680 °C to restore HAZ toughness.
What surface finishes work on 16Mo3-A?
No anodizing; protect by shot blasting plus epoxy/high-temperature silicone paint, aluminizing or thermal insulation, and control corrosion under insulation.
Can 16Mo3-A be formed, bent or molded?
Hot form at 900–1050 °C followed by re-normalizing; cold bending is practical to about 3t radius in annealed or normalized plate.
What is the maximum service temperature of 16Mo3-A?
16Mo3-A is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 16Mo3-N and 16Mo3-C?
N is the default condition — standard stocked condition for boiler plate, tube and pipe; fine-grained ferrite-pearlite with guaranteed elevated-temperature proof stress. C: cold-drawn tube or bar for tight tolerance and higher strength; must be normalized before use above design creep temperatures. Yield strength is 310 MPa in N versus 450 MPa in C.
Sources
- EN 10028-2 — Flat products of steels for pressure purposes, Part 2: Non-alloy and alloy steels with specified elevated temperature properties — CEN (2017)
- EN 10216-2 — Seamless steel tubes for pressure purposes, Part 2: Non-alloy and alloy steel tubes with specified elevated temperature properties — CEN (2020)
- EN 10222-2 — Steel forgings for pressure purposes, Part 2: Ferritic and martensitic steels with specified elevated temperature properties — CEN (2017)
- ASME SA-204 / ASTM A204 Grade A — Pressure Vessel Plates, Alloy Steel, Molybdenum — ASTM / ASME (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Boiler and pressure vessel steel 16Mo3 data sheet — Dillinger / Voestalpine (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.