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Steel 18Ni(200) Maraging Steel vs HP9-4-20

Steel · grade comparison

Steel 18Ni(200) Maraging Steel and HP9-4-20 are both steel grades. 18Ni(200) Maraging Steel is the stronger of the two: yield strength 1,400 MPa (203 ksi) against 1,210 MPa (175 ksi) for HP9-4-20, about 16% more; tensile strength follows at 1,450 MPa (210 ksi) vs 1,340 MPa (194 ksi). In exchange, HP9-4-20 is the more ductile: elongation 17% versus 12% for 18Ni(200) Maraging Steel. HP9-4-20 is stiffer (200 GPa vs 186 GPa) and HP9-4-20 conducts heat better (30 W/m·K vs 20.5 W/m·K).

18Ni(200) Maraging SteelChoose it when strength drives the design.

HP9-4-20Choose it when the part is bent, formed or impact-loaded.

18Ni(200) Maraging Steel vs HP9-4-20: properties

18Ni(200) Maraging SteelHP9-4-20

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

186 GPa27 Msi
200 GPa29 Msi

Shear Modulus

71 GPa10.3 Msi
78 GPa11.3 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

1,450 MPa210 ksi
1,340 MPa194 ksi

Yield Strength (0.2% offset)

1,400 MPa203 ksi
1,210 MPa175 ksi

Elongation at Break

12%
17%

Reduction in Area

60%
63%

Compressive Strength

1,420 MPa206 ksi
1,250 MPa181 ksi

Shear Strength

870 MPa126 ksi
800 MPa116 ksi

Fatigue Strength (Endurance Limit)

600 MPa87 ksi
650 MPa94.3 ksi

Fracture Toughness (K_IC)

155 MPa·√m141 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

400 HB
390 HB

Hardness, Rockwell C

43 HRC
42 HRC

Hardness, Vickers

420 HV
410 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

8 g/cm³0.29 lb/in³
7.83 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,413°C2,575 °F
1,420°C2,588 °F

Liquidus Temperature

1,450°C2,642 °F
1,490°C2,714 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

20.5 W/m·K11.8 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Specific Heat Capacity

452 J/kg·K0.11 BTU/lb·°F
460 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

10.1 µm/m·K5.6 µin/in·°F
11.8 µm/m·K6.6 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb

Min Service Temperature

-196°C-321 °F
-100°C-148 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.8 % IACS
—

Electrical Resistivity

4.5×10⁻⁷ Ω·m17.7 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.52 V
-0.6 V

Corrosion Resistance

25 / 100
15 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

30 / 100
28 / 100

Formability (cold)

15 / 100
25 / 100

Castability

45 / 100
—

Brazeability / Solderability

50 / 100
40 / 100

Polishability

80 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 30% · Weldability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

110 MJ/kg47,292 BTU/lb
42 MJ/kg18,057 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
3.4 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
70 L/kg8.4 gal/lb

Typical Recycled Content

30%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

181 kN·m/kg
171 kN·m/kg

Specific Stiffness (E / density)

23.3 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

5,269 kJ/m³
3,660 kJ/m³

Thermal Diffusivity

5.7 mm²/s
8.3 mm²/s

Thermal Shock Resistance Index

16
17

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale18Ni(200) Maraging SteelHP9-4-20

Manufacturing and finishing

Capability18Ni(200) Maraging SteelHP9-4-20
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

18Ni(200) Maraging Steel vs HP9-4-20 — frequently asked

Is 18Ni(200) Maraging Steel stronger than HP9-4-20?

Yes. 18Ni(200) Maraging Steel has a typical yield strength of 1,400 MPa (203 ksi) against 1,210 MPa (175 ksi) for HP9-4-20 — about 16% more. Tensile strength is 1,450 MPa (210 ksi) vs 1,340 MPa (194 ksi).

Which is cheaper, 18Ni(200) Maraging Steel or HP9-4-20?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

When should I choose 18Ni(200) Maraging Steel over HP9-4-20?

Pick 18Ni(200) Maraging Steel when strength drives the design. Pick HP9-4-20 when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18Ni(200) Maraging Steel and HP9-4-20 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.