# 4140 steel equivalents

4140 steel is nearest to EN 1.7225 (42CrMo4), JIS SCM440 and China GB 42CrMo. These are nearest equivalents, not identical grades: the governing standard or mill certificate decides.

| System | Designation |
|---|---|
| AISI / ASTM / SAE | 4140 |
| EN steel name | 42CrMo4 |
| EN steel number | 1.7225 |
| JIS | SCM440 |
| China GB | 42CrMo |

Family: Chromium-molybdenum alloy steel

## What it is

A medium-carbon chromium-molybdenum alloy steel. It through-hardens in moderate sections and is tough after quenching and tempering. It is widely sold pre-hardened, ready to machine.

## Typical uses

Shafts, spindles, gears, axles, tool holders, fixtures, die shoes and high-strength studs and bolts.

## Machining notes

Machines well annealed. Pre-hardened bar machines with carbide at reduced speed. Welding needs preheat and post-weld heat treatment.

## Related grades

- 4130 steel (1.7218): Lower-carbon chromoly, better for welding
- 1045 steel (1.0503): Plain carbon steel for lighter duty
- P20 tool steel (1.2311): Pre-hardened mould steel

Equivalents are nearest matches, not identical grades. The governing standard or mill certificate decides.

## FAQ

**What is the European equivalent of 4140 steel?**
The nearest EN grade is 1.7225, steel name 42CrMo4.

**What is the JIS equivalent of 4140 steel?**
The nearest Japanese grade is SCM440.

**What is the Chinese GB equivalent of 4140 steel?**
The nearest Chinese GB grade is 42CrMo.

**Is 1.7225 the same as 4140?**
1.7225 (42CrMo4) is the nearest European equivalent of 4140, not an identical grade. Composition limits and required properties differ in detail, so check the governing standard or the mill certificate when it matters.

**What is 4140 used for?**
Shafts, spindles, gears, axles, tool holders, fixtures, die shoes and high-strength studs and bolts.

Source page: https://machinistcharts.com/material/4140-steel/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)