# Guides

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

Short, practical reference articles for engineers, drafters and fabricators.

- [How to read Australian steel section designations](https://steelinfo.au/guides/reading-steel-designations/) — What 310UB40.4, 100x100x5.0SHS, 75x75x6EA and C20019 mean, and the difference between nominal and actual sizes.
- [Section properties explained](https://steelinfo.au/guides/section-properties-explained/) — A practical guide to A, I, Z, S, r, J, Iw, kf and compactness, and which property controls which design check.
- [Using the DXF section files](https://steelinfo.au/guides/using-dxf-files/) — How to insert the free DXF cross-sections into AutoCAD, BricsCAD, Revit or CAM software: units, layers, origin and scale.
- [Corrosion protection of structural steel](https://steelinfo.au/guides/corrosion-protection/) — Choosing paint, hot-dip galvanizing or duplex systems to AS/NZS 2312, and using surface area per tonne to estimate coating quantities.
- [Notation & calculation method](https://steelinfo.au/notation/) — Symbols and how every value on this site is calculated.
- [Steel materials & grades](https://steelinfo.au/materials/) — Structural, hollow, sheet, weathering, Q&T, wear, reinforcing, bolts and stainless.

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