# A572 Grade 50 steel equivalents

A572 Grade 50 steel is nearest to EN 1.0045 (S355JR), JIS SM490A and China GB Q355B. These are nearest equivalents, not identical grades: the governing standard or mill certificate decides.

| System | Designation |
|---|---|
| AISI / ASTM / SAE | A572 Gr 50 |
| EN steel name | S355JR |
| EN steel number | 1.0045 |
| JIS | SM490A |
| China GB | Q355B |

Family: High-strength low-alloy structural steel

## What it is

A high-strength low-alloy structural steel. It is stronger than A36 and is weldable, used where weight saving matters. Equivalents differ in specified strength and toughness tests, so check before substituting.

## Typical uses

Bridges, building columns and beams, crane and heavy equipment frames, trailers and towers.

## Machining notes

Similar to A36, slightly tougher. Remove mill scale before precision work.

## Related grades

- A36 steel (1.0038): Lower-strength structural grade

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

## FAQ

**What is the European equivalent of A572 Grade 50 steel?**
The nearest EN grade is 1.0045, steel name S355JR.

**What is the JIS equivalent of A572 Grade 50 steel?**
The nearest Japanese grade is SM490A.

**What is the Chinese GB equivalent of A572 Grade 50 steel?**
The nearest Chinese GB grade is Q355B.

**Is 1.0045 the same as A572 Gr 50?**
1.0045 (S355JR) is the nearest European equivalent of A572 Gr 50, 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 A572 Gr 50 used for?**
Bridges, building columns and beams, crane and heavy equipment frames, trailers and towers.

Source page: https://machinistcharts.com/material/a572-grade-50-steel/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)