Benchmark · 4 materials
Steel Gray Iron vs Steel Ductile Iron vs Steel 1006 vs Steel 1008
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 | Gray Iron | Ductile Iron | 1006 | 1008 |
|---|---|---|---|---|
| Yield strengthMPa | 140 MPa20 ksi | 275 MPa40 ksi | 165 MPa24 ksi | 170 MPa25 ksi |
| Tensile strengthMPa | 215 MPa31 ksi | 415 MPa60 ksi | 300 MPa44 ksi | 305 MPa44 ksi |
| Specific strengthMPa·cm³/g | 20 | 39 | 21 | 22 |
| Densityg/cm³ | 7.15 g/cm³0.258 lb/in³ | 7.1 g/cm³0.257 lb/in³ | 7.87 g/cm³0.284 lb/in³ | 7.87 g/cm³0.284 lb/in³ |
| Hardness (HB equiv.)HB | 180 HB | 200 HB | 86 HB | 86 HB |
| Max service temp°C | 400 °C752 °F | 400 °C752 °F | 400 °C752 °F | 400 °C752 °F |
| Min service temp°C | -20 °C-4 °F | -20 °C-4 °F | -20 °C-4 °F | -20 °C-4 °F |
| Electrical conductivity% IACS | 2.6 % IACS1.5 MS/m | 3.1 % IACS1.8 MS/m | 12 % IACS7 MS/m | 11 % IACS6.4 MS/m |
| Machinability/100 | Excellent85 / 100 | Very good75 / 100 | Fair50 / 100 | Fair50 / 100 |
| Weldability/100 | Not recommended10 / 100 | Poor25 / 100 | Excellent100 / 100 | Excellent100 / 100 |
| Formability/100 | Not recommended1 / 100 | Not recommended10 / 100 | Excellent95 / 100 | Excellent95 / 100 |
| Relative cost | $$ Standard | $$ Standard | $ Budget | $ Budget |
| Processes | CNC, Cast/Forge | CNC, Cast/Forge | Sheet | 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 strength140 MPa
250 MPafamily median 540 MPa1,270 MPa
Tensile strength215 MPa
420 MPafamily median 800 MPa1,750 MPa
Density7.15 g/cm³
7.8 g/cm³family median 7.85 g/cm³7.85 g/cm³
Hardness (HB equiv.)180 HB
134 HBfamily median 210 HB558 HB
Max service temp400 °C
200 °Cfamily median 400 °C540 °C
Electrical conductivity2.6 % IACS
5.7 % IACSfamily median 9.7 % IACS12 % IACS
Machinability85 / 100
29 / 100family median 75 / 10075 / 100
Relative cost22
14family median 2553
Gray IronDuctile Iron10061008
Strength versus weight
Manufacturing and finishing
| Capability | Gray Iron | Ductile Iron | 1006 | 1008 |
|---|---|---|---|---|
| CNC machining | Yes | Yes | — | — |
| Casting & forging | Yes | Yes | — | — |
| Sheet metal | — | — | Yes | Yes |
| Default condition | As Cast | As Cast | HR | HR |
| Min. machined wall | 0.8 mm | 0.8 mm | — | — |
| Best machined surface | 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 |
| 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.