We manufacture forging ingots, billets, and blooms in alloy steel specifically for SCM-420, tailored for high-performance engineering and case hardening applications. SCM-420 is a low carbon chromium-molybdenum alloy steel widely used for carburized components requiring high surface hardness combined with a tough and ductile core. It is specially designed for parts subjected to wear, shock loading, and repeated mechanical stress.
The chromium content enhances hardenability and wear resistance, while molybdenum improves strength, fatigue resistance, and resistance to temper brittleness. SCM-420 provides excellent machinability in the annealed condition and shows superior performance after carburizing and heat treatment, making it suitable for demanding automotive and engineering applications.
This steel offers a strong balance of durability, wear resistance, and reliability for high-performance mechanical components.
| Element | Content (%) | Function / effect |
| Carbon (c) | 0.18 – 0.23 | Provides core toughness and supports carburizing |
| Manganese (mn) | 0.60 – 0.85 | Improves hardenability and strength |
| Silicon (si) | 0.15 – 0.35 | Enhances strength and elasticity |
| Chromium (cr) | 0.90 – 1.20 | Improves hardenability and wear resistance |
| Molybdenum (mo) | 0.15 – 0.30 | Improves fatigue strength and high-temperature stability |
| Phosphorus (p) | Max 0.030 | Impurity; lower content improves toughness |
| Sulphur (s) | Max 0.030 | Impurity; controlled content improves machinability |
The heat treatment cycle can be customized based on case depth and service requirements.
SCM-420 has several international near equivalents, including:
SCM-420 is widely used for components requiring high wear resistance along with strong core toughness. Its excellent carburizing response ensures long service life and improved fatigue performance. Additionally, its reliable heat treatment characteristics and machinability help optimize manufacturing efficiency and product quality.
| Grade | Carbon (%) | Key applications | Heat treatment | Comments |
| SCM-420 | 0.18 – 0.23 | Gears, shafts, automotive components | Carburizing, quenching & tempering | Excellent case hardening steel |
| 20crmo4 | 0.17 – 0.24 | Engineering and automotive parts | Carburizing | European equivalent grade |
| Aisi 4120 | 0.18 – 0.23 | Transmission and machinery components | Carburizing | American equivalent |
| Din 1.7243 | 0.18 – 0.23 | Precision engineering parts | Carburizing | German equivalent grade |
SCM-420 is a premium chromium-molybdenum carburizing alloy steel designed for case hardening applications in automotive and engineering industries. It delivers excellent surface hardness, core strength, and durability for critical mechanical components.