We manufacture forging ingots, billets, and blooms in carbon steel specifically for 40C8, designed for medium strength engineering applications where a good balance of strength, toughness, and machinability is required.
40C8 is a medium carbon, unalloyed engineering steel widely used for general mechanical components. It offers better strength and wear resistance than lower carbon grades such as 30C8, while maintaining good machinability in the annealed or normalized condition.
Due to its controlled carbon and manganese content, 40C8 responds well to heat treatment and is suitable for components subjected to moderate mechanical loads.
| Element | Content (%) | Function / effect |
| Carbon (c) | 0.35 – 0.45 | Provides strength, hardness, and wear resistance |
| Manganese (mn) | 0.60 – 0.90 | Improves hardenability and toughness |
| Sulphur (s) | 0.050 max | Improves machinability when controlled |
| Phosphorus (p) | 0.050 max | Controlled to maintain toughness |
| Silicon (si) | 0.15 – 0.35 | Increases strength and elasticity |
| Chromium (cr) | Nil | Not intentionally added |
| Nickel (ni) | Nil | Not present |
| Molybdenum (mo) | Nil | Not present |
| Other elements | — | No significant alloying additions |
(properties may vary based on heat treatment and section size)
40C8 Has Several International Equivalents, Including:
40C8 Offers A Reliable Combination Of Strength, Toughness, And Affordability For Medium-Duty Engineering Applications. Its Ability To Be Heat Treated Allows Manufacturers To Achieve Improved Performance While Maintaining Cost Efficiency. Additionally, Its Availability And Ease Of Processing Make It A Widely Preferred Material Across Industries.
| Grade | Carbon (%) | Strength level | Typical applications |
| 30C8 | 0.25 – 0.35 | Low–medium | Light engineering parts |
| 40C8 | 0.35 – 0.45 | Medium | Shafts, pins, fasteners |
| 45 c8 | 0.40 – 0.50 | Medium–high | Gears, axles |
| C 45 | 0.40 – 0.50 | Medium–high | Automotive parts |
| 50C8 | 0.45 – 0.55 | High | Crankshafts, gears |
40C8 carbon steel is a reliable medium carbon grade offering a practical combination of strength, toughness, and machinability. It is ideal for general engineering and automotive applications where moderate load-bearing capability and cost-effective performance are required.
If you want, i can standardize all c8 grades (30C8 to 50C8) in one consolidated table or format this content exactly for your website or product catalog.