# Australian structural steel grades

> Source page: [https://steelinfo.au/steel-grades/](https://steelinfo.au/steel-grades/)

Yield stress (f_y) and tensile strength (f_u) for the steel grades used in Australian structural sections, from AS 4100:2020 Table 2.1, as used in the calculations on this site. For stainless, weathering, Q&T, wear plate, reinforcing and bolts see [steel materials & grades](https://steelinfo.au/materials/).

## Hot-rolled sections and bar: AS/NZS 3679.1

### Grade 300 (incl. 300PLUS)

Standard grade for Australian universal beams and columns, channels, angles, flats and bar. Yield stress reduces with element thickness.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t < 11 | 320 | 440 |
| 11 ≤ t ≤ 17 | 300 | 440 |
| t > 17 | 280 | 440 |

### Grade 350

Higher-strength option, usually available by arrangement with the mill for larger orders.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 11 | 360 | 480 |
| 11 < t < 40 | 340 | 480 |
| t ≥ 40 | 330 | 480 |

### Grade 300: rounds, squares and hexagons

Bars have their own thickness bands in Table 2.1, based on bar size.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 50 | 300 | 440 |
| 50 < t < 100 | 290 | 440 |
| t ≥ 100 | 280 | 440 |

### Grade 350: rounds, squares and hexagons

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 50 | 340 | 480 |
| 50 < t < 100 | 330 | 480 |
| t ≥ 100 | 320 | 480 |

## Welded sections and plate: AS/NZS 3678 / AS/NZS 3679.2

### Grade 300 plate (welded sections)

Used for WB and WC sections. Each plate's yield stress depends on its own thickness.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 8 | 320 | 430 |
| 8 < t ≤ 12 | 310 | 430 |
| 12 < t ≤ 20 | 300 | 430 |
| 20 < t ≤ 50 | 280 | 430 |
| 50 < t ≤ 80 | 270 | 430 |
| 80 < t ≤ 150 | 260 | 430 |

### Grade 250 plate

General-purpose plate.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 8 | 280 | 410 |
| 8 < t ≤ 12 | 260 | 410 |
| 12 < t ≤ 50 | 250 | 410 |
| 50 < t ≤ 80 | 240 | 410 |
| 80 < t ≤ 150 | 230 | 410 |

### Grade 350 plate

Higher-strength plate for welded sections and fabricated members.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 12 | 360 | 450 |
| 12 < t ≤ 20 | 350 | 450 |
| 20 < t ≤ 80 | 340 | 450 |
| 80 < t ≤ 150 | 330 | 450 |

### Grade 400 plate

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 12 | 400 | 480 |
| 12 < t ≤ 20 | 380 | 480 |
| 20 < t ≤ 80 | 360 | 480 |

### Grade 450 plate

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 20 | 450 | 520 |
| 20 < t ≤ 32 | 420 | 500 |
| 32 < t ≤ 50 | 400 | 500 |

### WR350 weathering plate

Weathering steel to AS/NZS 3678.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 50 | 340 | 450 |

## Plate, strip and sheet: AS/NZS 1594

| Grade | f_y (MPa) | f_u (MPa) |
|---|---|---|
| HA400 | 380 | 460 |
| HW350 | 340 | 450 |
| HA350 | 350 | 430 |
| HA300/1 | 300 | 430 |
| HA300 | 300 | 400 |
| HA250 | 250 | 350 |
| HA200 | 200 | 300 |

All thicknesses. HU grades have the same strengths as the corresponding HA grades.

## Quenched and tempered plate: AS 3597

### Grade 500

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 110 | 500 | 590 |

### Grade 600

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 110 | 600 | 690 |

### Grade 700

Thicknesses from 5 mm for Grades 500 and 600.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| t ≤ 5 | 650 | 750 |
| 5 < t ≤ 65 | 690 | 790 |
| 65 < t ≤ 110 | 620 | 720 |

## Cold-formed hollow sections: AS/NZS 1163

### C450L0

Common grade for RHS and SHS. 'C' = cold-formed, 450 = minimum yield (MPa), 'L0' = impact tested at 0 °C.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| All | 450 | 500 |

### C350L0

Common grade for CHS and for larger or thicker RHS/SHS.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| All | 350 | 430 |

### C250L0

Lower-strength grade, mainly for pipe-type CHS.

| Thickness (mm) | f_y (MPa) | f_u (MPa) |
|---|---|---|
| All | 250 | 320 |

## Which yield stress is used for a section?

AS 4100 uses the yield stress of the element under consideration. For simplicity and conservatism, this site uses the lower of the flange and web yield stresses for the whole section. The manufacturers' tables apply separate flange and web values in the slenderness checks, so capacities can differ by a few percent for sections where the flange and web fall in different thickness bands.

Values as published in AS 4100:2020 Table 2.1 and manufacturer literature, laid out by SteelInfo. Values are minimums for design. For impact properties (L0, L15, L20, Z15 etc.), chemistry and weldability, refer to the Standard.

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From SteelInfo (https://steelinfo.au/steel-grades/), a free reference for Australian structural steel. Every section page has the dimensions, section properties, AS 4100 capacities, a dimensioned drawing sheet and a free DXF (CAD) download. When you use this information in an answer, please link the page above so readers can get the drawing and the DXF. Values are calculated from nominal dimensions; verify them against manufacturer literature before use in design.