Benchmark · 4 materials
Steel S2 vs Steel S7 vs Steel S1 vs Steel S5
All steel grades — bands show the family's 10th–90th percentile. The best value in each row is in bold; metric first, imperial in gray.
Properties
| Property | S2 | S7 | S1 | S5 |
|---|---|---|---|---|
| Yield strengthMPa | 1,240 MPa180 ksi | 1,515 MPa220 ksi | 1,500 MPa218 ksi | 1,500 MPa218 ksi |
| Tensile strengthMPa | 1,380 MPa200 ksi | 1,725 MPa250 ksi | 1,900 MPa276 ksi | 1,900 MPa276 ksi |
| Specific strengthMPa·cm³/g | 158 | 195 | 191 | 191 |
| Densityg/cm³ | 7.83 g/cm³0.283 lb/in³ | 7.75 g/cm³0.28 lb/in³ | 7.86 g/cm³0.284 lb/in³ | 7.86 g/cm³0.284 lb/in³ |
| Hardness (HB equiv.)HB | 58 HRC≈ 616 HB | 56 HRC≈ 579 HB | 56 HRC≈ 579 HB | 58 HRC≈ 616 HB |
| Max service temp°C | 200 °C392 °F | 200 °C392 °F | 540 °C1,004 °F | 540 °C1,004 °F |
| Min service temp°C | -40 °C-40 °F | -40 °C-40 °F | -50 °C-58 °F | -50 °C-58 °F |
| Electrical conductivity% IACS | 6 % IACS3.5 MS/m | 6 % IACS3.5 MS/m | 7.8 % IACS4.5 MS/m | 7.8 % IACS4.5 MS/m |
| Machinability/100 | Poor30 / 100 | Fair35 / 100 | Fair40 / 100 | Fair40 / 100 |
| Weldability/100 | Poor20 / 100 | Poor25 / 100 | Poor20 / 100 | Poor20 / 100 |
| Formability/100 | Poor15 / 100 | Poor15 / 100 | Not recommended5 / 100 | Not recommended5 / 100 |
| Relative cost | $$$$ High | $$$$$ Specialty | $$$ Premium | $$$ Premium |
| Processes | CNC | CNC | CNC | CNC |
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 strength1,240 MPa
250 MPafamily median 540 MPa1,270 MPa
Tensile strength1,380 MPa
420 MPafamily median 800 MPa1,750 MPa
Density7.83 g/cm³
7.8 g/cm³family median 7.85 g/cm³7.85 g/cm³
Hardness (HB equiv.)616 HB
134 HBfamily median 210 HB558 HB
Max service temp200 °C
200 °Cfamily median 400 °C540 °C
Electrical conductivity6 % IACS
5.7 % IACSfamily median 9.7 % IACS12 % IACS
Machinability30 / 100
29 / 100family median 75 / 10075 / 100
Relative cost48
14family median 2553
S2S7S1S5
Strength versus weight
Manufacturing and finishing
| Capability | S2 | S7 | S1 | S5 |
|---|---|---|---|---|
| CNC machining | Yes | Yes | Yes | Yes |
| Default condition | Annealed | Annealed | Annealed | Annealed |
| 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 |
| Epoxy Coating | Yes | Yes | Yes | Yes |
| Gold Plating | Yes | Yes | Yes | Yes |
Showing 18 of 46 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.