Steel 18Kh2N4MA vs SCM415
Steel · grade comparison
Steel 18Kh2N4MA and SCM415 are both steel grades. 18Kh2N4MA is the stronger of the two: yield strength 980 MPa (142 ksi) against 430 MPa (62.4 ksi) for SCM415, about 128% more; tensile strength follows at 1,250 MPa (181 ksi) vs 640 MPa (92.8 ksi). In exchange, SCM415 is the more ductile: elongation 22% versus 13% for 18Kh2N4MA, and 18Kh2N4MA is harder (363 HB vs 180 HB). SCM415 runs hotter in service (400°C vs 200°C continuous) and SCM415 conducts heat better (44 W/m·K vs 33 W/m·K). On the shop floor, SCM415 machines more easily (good vs poor) and SCM415 welds better (good vs poor).
18Kh2N4MAChoose it when strength drives the design.
SCM415Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
18Kh2N4MA vs SCM415: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Reduction in Area 55%
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Resistivity
Electrical Conductivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 18Kh2N4MA | SCM415 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | HR |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| Black Oxide | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| E-Coating | — | Yes |
| HVOF Coating | — | Yes |
| Hot-Dip Galvanizing | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
18Kh2N4MA vs SCM415 — frequently asked
Is 18Kh2N4MA stronger than SCM415?
Yes. 18Kh2N4MA has a typical yield strength of 980 MPa (142 ksi) against 430 MPa (62.4 ksi) for SCM415 — about 128% more. Tensile strength is 1,250 MPa (181 ksi) vs 640 MPa (92.8 ksi).
Which is cheaper, 18Kh2N4MA or SCM415?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 18Kh2N4MA or SCM415?
SCM415. Its machinability rates good (58/100) against poor (22/100) for 18Kh2N4MA; for welding the order is SCM415 first (good, 55/100) then 18Kh2N4MA (poor, 22/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18Kh2N4MA and SCM415 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.