Benchmark · 4 materials
Steel SNCM439 vs Steel 4140 vs Steel 4150 vs Steel 4340
Side-by-side benchmark of 4 steel grades.
PropertiesHow to read this table
- The best value in each row is in bold.
- Values are typical room-temperature figures for the default condition (temper / grade as listed).
- Relative cost is a market tier, not a price — it moves with region and volume.
- Confirm against the certified mill / resin datasheet before design release.
How to read this table
- The best value in each row is in bold.
- Values are typical room-temperature figures for the default condition (temper / grade as listed).
- Relative cost is a market tier, not a price — it moves with region and volume.
- Confirm against the certified mill / resin datasheet before design release.
| Property | SNCM439 | 4140 | 4150 | 4340 |
|---|---|---|---|---|
| Yield strengthMPaksi | 690 MPa100 ksi | 655 MPa95 ksi | 760 MPa110 ksi | 860 MPa125 ksi |
| Tensile strengthMPaksi | 980 MPa142 ksi | 725 MPa105 ksi | 825 MPa120 ksi | 1,035 MPa150 ksi |
| Specific strengthMPa·cm³/g | 88 | 83 | 97 | 110 |
| Densityg/cm³lb/in³ | 7.85 g/cm³0.284 lb/in³ | 7.85 g/cm³0.284 lb/in³ | 7.85 g/cm³0.284 lb/in³ | 7.85 g/cm³0.284 lb/in³ |
| Hardness (HB equiv.)HB | 230 HB | 200 HB | 210 HB | 217 HB |
| Max service temp°C°F | 480 °C896 °F | 425 °C797 °F | 425 °C797 °F | 425 °C797 °F |
| Min service temp°C°F | -50 °C-58 °F | -40 °C-40 °F | -40 °C-40 °F | -40 °C-40 °F |
| Electrical conductivity% IACS | 9.7 % IACS5.6 MS/m | 7.8 % IACS4.5 MS/m | 7.8 % IACS4.5 MS/m | 7.8 % IACS4.5 MS/m |
| Machinability/100 | Very good75 / 100 | Good60 / 100 | Good55 / 100 | Fair50 / 100 |
| Weldability/100 | Very good75 / 100 | Good60 / 100 | Fair45 / 100 | Fair50 / 100 |
| Formability/100 | Fair40 / 100 | Fair45 / 100 | Fair35 / 100 | Fair35 / 100 |
| Relative cost | $$ Standard | $$ Standard | $$$ Premium | $$$ Premium |
| Processes | CNC, Sheet | CNC, Sheet, Cast/Forge | CNC, Sheet | CNC, Sheet |
Where each grade sits
One track per property; coloured markers are the compared grades, the shaded band is the steel family 10th–90th percentile and the tick its median.
Yield strength690 MPa100 ksi
250 MPa36 ksifamily median 540 MPa78 ksi1,270 MPa184 ksi
Tensile strength980 MPa142 ksi
420 MPa61 ksifamily median 800 MPa116 ksi1,750 MPa254 ksi
Density7.85 g/cm³0.284 lb/in³
7.8 g/cm³0.282 lb/in³family median 7.85 g/cm³0.284 lb/in³7.85 g/cm³0.284 lb/in³
Hardness (HB equiv.)230 HB
134 HBfamily median 210 HB558 HB
Max service temp480 °C896 °F
200 °C392 °Ffamily median 400 °C752 °F540 °C1,004 °F
Electrical conductivity9.7 % IACS
5.7 % IACSfamily median 9.7 % IACS12 % IACS
Machinability75 / 100
29 / 100family median 75 / 10075 / 100
Relative cost31
14family median 2553
SNCM439414041504340
Strength versus weight
Manufacturing and finishing
| Capability | SNCM439 | 4140 | 4150 | 4340 |
|---|---|---|---|---|
| CNC machining | Yes | Yes | Yes | Yes |
| Sheet metal | Yes | Yes | Yes | Yes |
| Casting & forging | — | Yes | — | — |
| Default condition | HR | HR | HR | HR |
| Min. machined wall | 0.8 mm | 0.8 mm | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm | Ra 1.6 µm | Ra 1.6 µm |
| Heat treatments | Quench & Temper, Full Anneal, Stress Relief | Quench & Temper, Full Anneal, Stress Relief | Quench & Temper, Full Anneal, Stress Relief | Quench & Temper, Full Anneal, Stress Relief |
| AlCrN | Yes | Yes | Yes | Yes |
| AlTiN | Yes | Yes | Yes | Yes |
| Black Oxide | Yes | Yes | Yes | Yes |
| CVD Al2O3 | Yes | Yes | Yes | Yes |
| CVD TiCN | Yes | Yes | Yes | Yes |
| CVD TiN | Yes | Yes | Yes | Yes |
| Cerakote | Yes | Yes | Yes | Yes |
| Chemical Etching | Yes | Yes | Yes | Yes |
| Chrome Plating | Yes | Yes | Yes | Yes |
| Copper Plating | Yes | Yes | Yes | Yes |
| CrN | Yes | Yes | Yes | Yes |
| DLC | Yes | Yes | Yes | Yes |
| Dot Peen Marking | Yes | Yes | Yes | Yes |
| E-Coating | Yes | Yes | Yes | Yes |
| Electro-chemical Etching | Yes | Yes | Yes | Yes |
| Electroless Nickel (EN) | Yes | Yes | Yes | Yes |
| Embossing / Debossing | Yes | Yes | Yes | Yes |
| Epoxy Coating | Yes | Yes | Yes | Yes |
Showing 18 of 47 finishes — the full list is on each grade's datasheet.
Typical handbook values for the default condition, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.