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Steel Maraging 300 As Printed

Print state · default condition

UNS K93120 · AISI/SAE 18Ni300 · ASTM A538 Grade C · EN 1.2709, 1.6358 · also Vascomax C-300

Pick for as-built LPBF parts before any heat treatment: already ~35 HRC, but with residual stress and slight anisotropy.

Values for the As Printed condition

Other Maraging 300 tempers and conditions

Maraging 300 is listed in 4 conditions; see the grade overview at Maraging 300.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
AnnealedDefault
solution annealed 815–830 °C, air cooled (soft martensite)
Standard supply condition of wrought bar/plate: soft enough to machine, form and weld before final aging.8001,0101730 HRC—
post-build/post-weld stress relief (typ. 815 °C/1 h or 490 °C short cycle)
Use on AM or welded parts to remove residual stress and prevent distortion during machining, before final aging.9501,1001433 HRC2.8 % IACS
As PrintedDefaultThis page
laser powder-bed fusion (MS1 / 1.2709 3DP), as-built
Pick for as-built LPBF parts before any heat treatment: already ~35 HRC, but with residual stress and slight anisotropy.1,0001,1301235 HRC15 W/m·K
Precipitation aged 480–500 °C / 3–6 h, air cooled
Final service condition: ~2000 MPa strength and 50–54 HRC with minimal distortion — choose for tooling, mold inserts and high-strength structural parts.1,9001,950752 HRC20 W/m·K

What is Maraging 300 As Printed?

Maraging 300 As Printed is Maraging 300 in the As Printed condition — pick for as-built LPBF parts before any heat treatment: already ~35 HRC, but with residual stress and slight anisotropy. Maraging 300 As Printed has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 180 GPa (26.1 Msi). Maraging 300 As Printed 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).

Advantages

  • Polishes to a fine finish — 85/100, better than 99% of steel grades
  • Good corrosion resistance — 25/100, better than 92% of steel grades
  • High strength — 800 MPa (116 ksi), better than 86% of steel grades
  • Readily welded — 80/100, better than 79% of steel grades

Limitations

  • High embodied carbon — 6.5 kg CO₂/kg, worse than 98% of steel grades
  • Low stiffness — 180 GPa (26.1 Msi), worse than 96% of steel grades
  • Poor heat conductor — 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades
  • Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades

Maraging 300 As Printed properties

Typical room-temperature values for Maraging 300 As Printed; 11 are specific to this condition. Other listed values are Maraging 300 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

Maraging 300 As Printed 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).

Density8 g/cm³0.29 lb/in³
Melting Point (Solidus)1,413°C2,575 °F
Liquidus Temperature1,450°C2,642 °F

Mechanical15

Maraging 300 As Printed has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 86% of steel grades. Elongation at break is 17% and the elastic modulus is 180 GPa (26.1 Msi).

Elastic (Young's) Modulus180 GPa26.1 Msi
Shear Modulus70 GPa10.2 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)1,010 MPa146 ksi
Yield Strength (0.2% offset)800 MPa116 ksi
Elongation at Break17%
Reduction in Area72%
Compressive Strength830 MPa120 ksi
Shear Strength620 MPa89.9 ksi
Fatigue Strength (Endurance Limit)450 MPa65.3 ksi
Charpy V-Notch Impact (RT)100 J73.8 ft·lbf
Hardness, Brinell300 HB
Hardness, Rockwell C30 HRC
Hardness, Vickers315 HV

Thermal6

Maraging 300 As Printed is rated for continuous service to 400°C (752 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).

Thermal Conductivity20 W/m·K11.6 BTU/hr·ft·°F
Specific Heat Capacity450 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)10.3 µm/m·K5.7 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-196°C-321 °F

Electrical3

Maraging 300 As Printed conducts electricity at 2.9 % IACS, worse than 93% of steel grades.

Electrical Conductivity2.9 % IACS
Electrical Resistivity6×10⁻⁷ Ω·m23.6 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is poor (25/100), better than 92% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.58 V
Corrosion ResistancePoor25/100
Chemical Resistance SummaryNot stainless: rusts in humid air, salt spray and water; needs oil, phosphating, Ni/Cr plating or nitriding. Resists dry gases and most oils; attacked by acids and chlorides; risk of hydrogen embrittlement when acid-pickled or electroplated without bake-out.

Sustainability4

Producing a kilogram of Maraging 300 As Printed takes about 100 MJ of energy and emits 6.5 kg of CO₂ — more than 99% of steel grades. Typical recycled content is 20%.

Embodied Energy (primary production)100 MJ/kg42,992 BTU/lb
Embodied Carbon (primary production)6.5 kg CO₂/kg
Embodied Water250 L/kg30 gal/lb
Typical Recycled Content20%

Manufacturability8

Maraging 300 As Printed's machinability is fair (45/100, worse than 65% of steel grades); weldability very good (80/100); formability good (55/100).

MachinabilityFair45/100
Machinability Rating (AISI 1212 = 100 %)50%
WeldabilityVery good80/100
Formability (cold)Good55/100
CastabilityFair40/100
Brazeability / SolderabilityFair45/100
PolishabilityExcellent85/100
Anodizing Responsen/a — ferrous alloy; use nitriding, hard chrome, electroless Ni or PVD instead

Common Calculations5

Specific Strength (UTS / density)calculated126 kN·m/kg
Specific Stiffness (E / density)calculated22.5 MN·m/kg
Modulus of Resiliencecalculated1,778 kJ/m³
Thermal Diffusivitycalculated5.6 mm²/s
Thermal Shock Resistance Indexcalculated11

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Maraging 300 As Printed

Is Maraging 300 easy to machine?

Machine in the annealed/stress-relieved state with sharp carbide, rigid setups and generous coolant; aged 52 HRC material needs ceramic/CBN or grinding, and aging shrinks parts only ~0.05 %.

Can Maraging 300 be welded?

Excellent — TIG/laser/EB weld with matching filler, no preheat, low heat input and clean surfaces; re-age the weldment at 480–500 °C to restore joint strength.

Can Maraging 300 be formed, bent or molded?

Cold form, bend and deep draw only in the annealed condition (elongation ~17 %); hot work 900–1200 °C, then solution anneal — no cold forming after aging.

What surface finishes work on Maraging 300?

Takes a mirror polish (widely used for mold cavities) but is not stainless: protect with nitriding, hard chrome, electroless Ni, PVD or oil, and bake after any electroplating to avoid hydrogen embrittlement.

Maraging 300 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.

ElementSpec limit (wt %)Nominal
Cultra-low carbon essential to toughness≤ 0.030.01
Ni18 – 1918.5
Co8.5 – 9.59
Moforms Ni3Mo precipitates4.6 – 5.24.9
Ti0.5 – 0.80.65
Al0.05 – 0.150.1
Si≤ 0.10.05
Mn≤ 0.10.05
P≤ 0.01
S≤ 0.01
Febalance

Maraging 300 As Printed — frequently asked

What is Maraging 300 As Printed used for?

Maraging 300 As Printed is typically used for rocket motor cases and pressure shells, additively manufactured mold inserts with conformal cooling, die and punch tooling inserts, aerospace structural fittings and actuator parts, high-torque drive shafts and couplings and motorsport and aerospace fasteners. In short: premium aerospace maraging bar.

What is the yield strength of Maraging 300 As Printed?

Maraging 300 As Printed has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,010 MPa (146 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 4 listed tempers.

Is Maraging 300 As Printed easy to machine?

Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed/stress-relieved state with sharp carbide, rigid setups and generous coolant; aged 52 HRC material needs ceramic/CBN or grinding, and aging shrinks parts only ~0.05 %.

Can Maraging 300 As Printed be welded?

Yes — weldability is rated very good (80/100). Excellent — TIG/laser/EB weld with matching filler, no preheat, low heat input and clean surfaces; re-age the weldment at 480–500 °C to restore joint strength.

What surface finishes work on Maraging 300 As Printed?

Takes a mirror polish (widely used for mold cavities) but is not stainless: protect with nitriding, hard chrome, electroless Ni, PVD or oil, and bake after any electroplating to avoid hydrogen embrittlement.

Can Maraging 300 As Printed be formed, bent or molded?

Cold form, bend and deep draw only in the annealed condition (elongation ~17 %); hot work 900–1200 °C, then solution anneal — no cold forming after aging.

What is the maximum service temperature of Maraging 300 As Printed?

Maraging 300 As Printed 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 Maraging 300 Annealed and Maraging 300 Aged?

Annealed is the default condition — standard supply condition of wrought bar/plate: soft enough to machine, form and weld before final aging. Aged: final service condition: ~2000 MPa strength and 50–54 HRC with minimal distortion — choose for tooling, mold inserts and high-strength structural parts. Yield strength is 800 MPa in Annealed versus 1,900 MPa in Aged.

Can FabDigit make parts in Maraging 300 As Printed?

Yes — Maraging 300 As Printed is available for CNC machining, sheet metal and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASM Specialty Handbook: Tool Materials / Maraging Steels — ASM International (1995)
  2. ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
  3. AMS 6514 / ASTM A538 Grade C (18Ni-300 maraging steel) — SAE / ASTM (2019)
  4. DIN EN ISO 4957 / Werkstoff 1.2709 — DIN (2018)
  5. EOS MaragingSteel MS1 material data sheet — EOS GmbH (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.