# Steel materials & grades

> Source page: [https://steelinfo.au/materials/](https://steelinfo.au/materials/)

An overview of the steels used in Australian construction and fabrication: what each is called, which Standard covers it, and what it is used for. The *section* (e.g. 310UB40.4) describes the shape; the *grade* describes the steel it is made from.

## Structural carbon steel

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Hot-rolled sections & bar** | 300 (300PLUS), 350 | AS/NZS 3679.1 | 280–360 | Universal beams and columns, channels, angles, flats, rounds | Yield reduces with thickness. See [steel grades](https://steelinfo.au/steel-grades/). |
| **Structural plate** | 250, 300, 350, 400, 450 | AS/NZS 3678 | 230–450 | Welded beams and columns, base plates, gussets, stiffeners | L0/L15/L20 suffixes indicate impact-tested grades. |
| **Hot-rolled coil, sheet & floorplate** | HA200–HA400, HW350, XF300–XF500 | AS/NZS 1594 | 200–480 | Folded plates, chequer floorplate, light fabrications | Commercial grades (HA1, HA3) have no guaranteed yield. |
| **Cold-formed hollow sections** | C250L0, C350L0, C450L0 | AS/NZS 1163 | 250–450 | CHS, SHS and RHS columns, trusses, frames | Supplied clear, pre-galvanised (in-line) or hot-dip galvanised. |
| **Metallic-coated sheet & strip** | G250, G300, G450, G500, G550 | AS 1397 | 250–550 | Purlins, girts, roofing, light-gauge framing | Coating classes such as Z275, Z350, Z450 and AZ150 (zinc/aluminium). |

## Weathering steel

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Weathering plate & sheet** | WR350, REDCOR | AS/NZS 3678, AS/NZS 1594 | 340 | Exposed architectural and bridge steelwork, landscaping | Forms a protective patina. Not for marine, wet or crevice-prone details. |

## High-strength plate

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Quenched & tempered plate** | Grade 500, 600, 700 (e.g. Bisplate 60/70/80) | AS 3597 | 500–690 | Cranes, mining equipment, heavy transport, lightweight high-load structures | Needs controlled welding procedures (preheat, low-hydrogen). |

## Wear-resistant plate

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Abrasion-resistant plate** | 400, 450, 500 HB (e.g. Bisalloy 400, Hardox 450) | Manufacturer specification | – | Chutes, liners, buckets, truck bodies | Specified by hardness, not yield. Generally not used as structural steel. |

## Reinforcing steel

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Reinforcing bar & mesh** | D500N, D500L, R250N | AS/NZS 4671 | 250–500 | Concrete reinforcement, mesh, ligatures | N = normal ductility, L = low ductility (mesh), R = round bar. |

## Fasteners

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Structural bolts** | Property class 4.6, 8.8, 10.9 | AS 1111, AS 1110, AS/NZS 1252.1 | 240 / 660 / 940 (fu 400 / 830 / 1040) | Bolted connections (4.6/S, 8.8/S, 8.8/TB, 8.8/TF and the 10.9 categories) | TB and TF bolts are fully tensioned; TF are friction-type. Grade 8.8 below M16: fu 800. 10.9 was added in AS 4100:2020. |

## Stainless steel

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Austenitic stainless** | 304/304L, 316/316L | ASTM A240, AS/NZS 4673 | ≈ 170–205 (0.2% proof) | Handrails, balustrades, food and marine environments | 316 has molybdenum for better pitting resistance. Avoid contact with carbon steel. |
| **Duplex stainless** | 2205 (1.4462) | ASTM A240, AS/NZS 4673 | ≈ 450 (0.2% proof) | Marine, chemical and high-strength stainless structures | About twice the proof stress of 304/316. |

## Engineering steel

| Product | Typical grades | Standard | Min. yield (MPa) | Typical uses | Notes |
|---|---|---|---|---|---|
| **Carbon & alloy bar** | 1020, 1045, 4140, 4340 | AS 1442, AS 1444 | Depends on condition | Pins, shafts, bushes, machined parts | Properties depend strongly on heat treatment and size; check the supplier certificate. |

Values are indicative minimums. Yield strength usually reduces with thickness. Always specify the grade and Standard on drawings and check mill certificates. Detailed yield/tensile tables for structural grades are on the [steel grades](https://steelinfo.au/steel-grades/) page.

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From SteelInfo (https://steelinfo.au/materials/), 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.