SCM420 steel is one of popular alloy steel used as engineering steel. Fushun Specialsteel is one of leading supplier of SCM420 steel materials in reliable quality.
SCM420 Steel one steel grade in JIS standard. SCM420 steel is one of popular alloy steel used for engineering purpose, like fasteners, high pressure pipe and more advanced carburized parts, such as gear, shaft, etc. which work in the noncorrosive medium and temperature below 250 ℃, working with nitrogen hydrogen mixture in the medium.
The quench-hardening ability of SCM420 steel is higher, no temper brittleness. The weldability of SCM420 steel is also very good, with excellent machining or cutting properties. The tendency of cold crack formation is very small, but machinability and cold straining plasticity is still good.
International Comparison of Materials
| EU EN |
INTER ISO | USA AISI |
JAPAN JIS |
GERMANY DIN |
CHINA GB |
FRANCE AFNOR |
ITALY UNI |
|---|---|---|---|---|---|---|---|
| 25CrMo4 | 25CrMo4 | 4130 | SCM420 | 25CrMo4 | 30CrMn | 25CD4 | 25CrMo4(KB) |
| SPAIN UNE |
Sweden SS |
Finland SFS |
Poland PN |
Czechia CSN |
Austria ONORM |
Russia GOST |
England BS |
|---|---|---|---|---|---|---|---|
| 55Cr3 | 2225 | 25CrMo4 | — | — | — | 20ChM | 1717CDS110 |
Available Types & Range
| Form of Supply | Size(mm) | Length(mm) |
| Round bar | Φ32 – 150 | Standard or As your request |
Chemical Composition & Technical Specification –SCM 420
| C(%) | Si(%) | Mn(%) | P(%) | S(%) | Ni(%) | Cr(%) | Mo(%) | Cu(%) |
|---|---|---|---|---|---|---|---|---|
| 0.18-0.23 | 0.15-0.35 | 0.6-0.85 | 0≦0.03 | 0≦0.03 | 0≦0.25 | 0.9-1.2 | 0.15-0.30 | 0≦0.3 |
Conditions of heat treatment
- Annealing: 850℃ Furnace Cooling
- Normalization: 850~900℃ Air Cooling
- Hardening: 850~900℃ 1st Oil Cooling, 800~850℃ 2rd Oil Cooling
- Tempering: 150~200℃ Air Cooling
Criterion for heat treating conditions revise:
- Ac: 770~835℃
- Ar: 770~700℃
- Ms: 410℃
Mechanical properties
Tensile strength (kgf/mm²): ≧95
Elongation (%): ≧14
Cross section reduction rate (%): ≧40
Impact value (J/cm2): ≧6
Hardness (Hb) : 352~362
Application of SCM420 Alloy Steel
SCM420 case hardening alloy steels are widely used as gear components of all kind and cog wheels. Open die steel forgings for general engineering purposes. Otai steel are available to supply different size of SCM420 steel and is able to supply modified 4118/SCM420/18CrMo4 steel composition according to different requirements.
