Benchmark · 4 materials
Steel Ductile Iron vs Steel Gray Iron vs Steel 1006 vs Steel 1008
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 | Ductile Iron | Gray Iron | 1006 | 1008 |
|---|---|---|---|---|
| Yield strengthMPaksi | 275 MPa40 ksi | 140 MPa20 ksi | 165 MPa24 ksi | 170 MPa25 ksi |
| Tensile strengthMPaksi | 415 MPa60 ksi | 215 MPa31 ksi | 300 MPa44 ksi | 305 MPa44 ksi |
| Specific strengthMPa·cm³/g | 39 | 20 | 21 | 22 |
| Densityg/cm³lb/in³ | 7.1 g/cm³0.257 lb/in³ | 7.15 g/cm³0.258 lb/in³ | 7.87 g/cm³0.284 lb/in³ | 7.87 g/cm³0.284 lb/in³ |
| Hardness (HB equiv.)HB | 200 HB | 180 HB | 86 HB | 86 HB |
| Max service temp°C°F | 400 °C752 °F | 400 °C752 °F | 400 °C752 °F | 400 °C752 °F |
| Min service temp°C°F | -20 °C-4 °F | -20 °C-4 °F | -20 °C-4 °F | -20 °C-4 °F |
| Electrical conductivity% IACS | 3.1 % IACS1.8 MS/m | 2.6 % IACS1.5 MS/m | 12 % IACS7 MS/m | 11 % IACS6.4 MS/m |
| Machinability/100 | Very good75 / 100 | Excellent85 / 100 | Fair50 / 100 | Fair50 / 100 |
| Weldability/100 | Poor25 / 100 | Not recommended10 / 100 | Excellent100 / 100 | Excellent100 / 100 |
| Formability/100 | Not recommended10 / 100 | Not recommended1 / 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 strength275 MPa40 ksi
250 MPa36 ksifamily median 540 MPa78 ksi1,270 MPa184 ksi
Tensile strength415 MPa60 ksi
420 MPa61 ksifamily median 800 MPa116 ksi1,750 MPa254 ksi
Density7.1 g/cm³0.257 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.)200 HB
134 HBfamily median 210 HB558 HB
Max service temp400 °C752 °F
200 °C392 °Ffamily median 400 °C752 °F540 °C1,004 °F
Electrical conductivity3.1 % IACS
5.7 % IACSfamily median 9.7 % IACS12 % IACS
Machinability75 / 100
29 / 100family median 75 / 10075 / 100
Relative cost25
14family median 2553
Ductile IronGray Iron10061008
Strength versus weight
Manufacturing and finishing
| Capability | Ductile Iron | Gray 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.