Steel C300 Normalized
Heat-treated state
EN 18Ni Maraging 300 · AMS 6514
Intermediate treatment used to refine coarse as-cast/as-forged grain before the 815 °C solution anneal; not a final delivery condition.
Values for the Normalized condition
Other C300 tempers and conditions
C300 is listed in 8 conditions; see the grade overview at C300.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
NormalizedThis page 900–980 °C grain-refining anneal + air cool (intermediate homogenising treatment) | Intermediate treatment used to refine coarse as-cast/as-forged grain before the 815 °C solution anneal; not a final delivery condition. | 790 | 1,000 | 16 | 31 HRC | 2.9 % IACS |
solution annealed 815 °C / 1 h, air cool (as-supplied soft martensite) | Standard as-shipped condition (~30 HRC): machine, form and weld here, then age to final strength. | 800 | 1,010 | 17 | 30 HRC | — |
HRDefault Hot rolled | Mill hot-worked stock with scale and looser tolerances; solution anneal and age before use. | 850 | 1,050 | 13 | 32 HRC | 2.9 % IACS |
Cold drawn | Bright, close-tolerance bar or wire with modest cold-work strengthening; still machinable and can be aged afterwards. | 1,000 | 1,150 | 10 | 34 HRC | 2.9 % IACS |
Cold rolled | Thin sheet and strip with smooth surface and light cold work; formed to shape then aged (weld first, age last). | 1,050 | 1,180 | 7 | 35 HRC | 2.9 % IACS |
Quenched and tempered | For maraging C300 the hardened condition is solution anneal at 815-830 °C, air cool, then age 3-6 h at 480 °C, giving about 1930 MPa tensile and 52-56 HRC with near-zero distortion instead of a conventional quench-and-temper cycle. | 1,860 | 1,930 | 8 | 54 HRC | 3.1 % IACS |
solution annealed + 480 °C / 3–6 h, air cool | Final full-strength condition (~53 HRC, ~1950 MPa) for aerospace structure, tooling and rotor parts; minimal distortion during aging. | 1,900 | 1,965 | 8 | 53 HRC | 3.8 % IACS |
Cold worked (≈20–50 % reduction) then maraged 480 °C | Highest-strength route for wire, thin strip and springs; strength above 2100 MPa at the cost of ductility and toughness. | 2,050 | 2,120 | 5 | 55 HRC | — |
What is C300 Normalized?
C300 Normalized is C300 heat treated to Normalized — intermediate treatment used to refine coarse as-cast/as-forged grain before the 815 °C solution anneal; not a final delivery condition. C300 Normalized has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 16% and the elastic modulus is 186 GPa (27 Msi). C300 Normalized has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,413°C (2,575 °F). HR is the default condition FabDigit quotes; Normalized is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 78/100, better than 95% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% of steel grades
- Good corrosion resistance — 22/100, better than 90% of steel grades
- High strength — 790 MPa (115 ksi), better than 86% of steel grades
- Readily welded — 82/100, better than 81% of steel grades
Limitations
- High embodied carbon — 7 kg CO₂/kg, worse than 99% of steel grades
- Poor heat conductor — 19.5 W/m·K (11.3 BTU/hr·ft·°F), worse than 97% of steel grades
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
C300 Normalized properties
Typical room-temperature values for C300 Normalized; 22 are specific to this condition. Other listed values are C300 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
C300 Normalized has a density of 8 g/cm³ (0.289 lb/in³), heavier than 95% of steel grades. It melts at 1,413°C (2,575 °F).
Mechanical16
C300 Normalized has a yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 16% and the elastic modulus is 186 GPa (27 Msi).
Thermal6
C300 Normalized is rated for continuous service to 400°C (752 °F). It conducts heat at 19.5 W/m·K (11.3 BTU/hr·ft·°F), worse than 97% of steel grades. Thermal expansion is 10.1 µm/m·K (5.61 µin/in·°F).
Electrical3
C300 Normalized conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of C300 Normalized takes about 105 MJ of energy and emits 7 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 20%.
Manufacturability7
C300 Normalized's machinability is fair (44/100, worse than 71% of steel grades); weldability very good (82/100); formability good (63/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C300 Normalized
Is C300 easy to machine?
Machine in the annealed condition (~30 HRC) with sharp carbide tooling, rigid setups and generous coolant; it is gummy and work-hardens, so use positive rake, moderate speeds and heavy feeds — aged material at 53 HRC needs grinding or ceramic/CBN finishing.
Can C300 be welded?
Excellent weldability by GTAW/EB/laser with matching low-carbon filler, no preheat and low heat input; solution-anneal or at minimum re-age at 480 °C after welding to restore joint strength, and keep the weld area free of oil, moisture and hydrogen.
Can C300 be formed, bent or molded?
Form, bend, deep-draw or spin in the annealed state where ductility is 15–20 %; aging causes only ~0.05–0.1 % uniform shrinkage, so finished dimensions are predictable after heat treatment.
What surface finishes work on C300?
Not corrosion resistant — protect with nitriding (raises surface to 65+ HRC), hard chrome, electroless nickel, cadmium/zinc-nickel or phosphate plus paint; avoid embrittling acid pickling and always bake after electroplating to relieve hydrogen.
C300 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 |
|---|---|---|
| Cultra-low carbon is essential | ≤ 0.03 | 0.01 |
| Ni | 18 – 19 | 18.5 |
| Co | 8.5 – 9.5 | 9 |
| Moforms Ni3Mo on aging | 4.6 – 5.2 | 4.9 |
| Timain strength lever vs 18Ni-250 | 0.55 – 0.8 | 0.65 |
| Al | 0.05 – 0.15 | 0.1 |
| Si | ≤ 0.1 | 0.05 |
| Mn | ≤ 0.1 | 0.05 |
| P | ≤ 0.01 | 0.01 |
| S | ≤ 0.01 | 0 |
| Bgrain-boundary addition (optional) | ≤ 0 | 0 |
| Zroptional addition | ≤ 0.02 | 0.01 |
| Caoptional deoxidiser | ≤ 0.05 | 0.02 |
| Fe | balance | — |
C300 Normalized — frequently asked
What is C300 Normalized used for?
C300 Normalized is typically used for rocket motor cases, missile bodies, centrifuge rotors, aerospace structural fittings, die-casting dies and high-strength tooling and punches. In short: ultra-strong maraging steel.
What is the yield strength of C300 Normalized?
C300 Normalized has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is C300 Normalized easy to machine?
Not especially — machinability is rated fair (44/100, worse than 71% of steel grades). Machine in the annealed condition (~30 HRC) with sharp carbide tooling, rigid setups and generous coolant; it is gummy and work-hardens, so use positive rake, moderate speeds and heavy feeds — aged material at 53 HRC needs grinding or ceramic/CBN finishing.
Can C300 Normalized be welded?
Yes — weldability is rated very good (82/100). Excellent weldability by GTAW/EB/laser with matching low-carbon filler, no preheat and low heat input; solution-anneal or at minimum re-age at 480 °C after welding to restore joint strength, and keep the weld area free of oil, moisture and hydrogen.
What surface finishes work on C300 Normalized?
Not corrosion resistant — protect with nitriding (raises surface to 65+ HRC), hard chrome, electroless nickel, cadmium/zinc-nickel or phosphate plus paint; avoid embrittling acid pickling and always bake after electroplating to relieve hydrogen.
Can C300 Normalized be formed, bent or molded?
Form, bend, deep-draw or spin in the annealed state where ductility is 15–20 %; aging causes only ~0.05–0.1 % uniform shrinkage, so finished dimensions are predictable after heat treatment.
What is the maximum service temperature of C300 Normalized?
C300 Normalized is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C300-HR and C300 Aged?
HR is the default condition — mill hot-worked stock with scale and looser tolerances; solution anneal and age before use. Aged: final full-strength condition (~53 HRC, ~1950 MPa) for aerospace structure, tooling and rotor parts; minimal distortion during aging. Yield strength is 850 MPa in HR versus 1,900 MPa in Aged.
Can FabDigit make parts in C300 Normalized?
Yes — C300 Normalized 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
- AMS 6514 — Steel, Maraging, Bars, Forgings, Tubing and Rings, 18.5Ni-9.0Co-4.9Mo-0.65Ti — SAE International (2019)
- AMS 6521 — Maraging 300 Sheet, Strip and Plate — SAE International (2018)
- ASTM A538/A538M — Pressure Vessel Plates, Maraging Steels (Grade C, 18Ni-300) — ASTM (2018)
- ASM Specialty Handbook: Tool Materials / Maraging Steels chapter — ASM International (1995)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- VascoMax C300 maraging steel datasheet — Carpenter Technology / Latrobe (2021)
- MMPDS-2023 maraging steel allowables — Battelle/FAA (2023)
- GB/T 34474 / 00Ni18Co9Mo5TiAl (2017)
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.