A beginner’s guide to structural steel beams

Structural steel beams are used in a variety of applications, thanks to their versatility, strength and affordability.

Edcon Steel stocks and sells a range of structural beams, columns and channels, which are a great solution for a range of applications, including house building and renovations, construction, infrastructure, strutting beams, floor bearer beams, verandah beams and lintel beams and rafters.

Using Structural Steel in Housing, we have compiled a guide for beginners to assist you in choosing the right product from our range.

Builder’s steel 101 has more useful information on steel terms, ideas and applications of structural steel beams.

Universal Beams

Universal Beams (UBs) are often referred to in the industry as I-Beams or H-Beams. UBs are made using mild steel grade 300 plus (300 MPa yield strength) and are stocked at Edcon Steel in a mill finish.

Being such a widely used product, different customers will have different names for structural beams including H-shaped beam or H-Beam, I-shaped beam or I-Beam, RSJ, steel joist, steel beam or even just steels. Universal Beams are designed to carry high loads over long spans.

UBs are ‘I’ shaped (when standing up like an ‘I’ – pictured) with the following features:

1. Thick flanges (top and base of the I) and thinner web (upright of the I).
2. The I is higher than the base.

To size a Universal Beam there are 2 sets of numbers.  These numbers are a combination of the sizes of the beam and it weight per metre.

Figure 1 shows how to interpret this combination of letters and numbers.

Taper Flange Beams (TFB or RSJ)

Taper Flange Beams are very similar to the Universal Beams, apart from the flanges, which are typically tapered at an angle of 98 degrees to the web. There are only two sizes of TFB available in the Australian market – 100 and 125 TFB.

Universal Columns (UC)

Universal Columns are thicker and wider ‘I’ sections. As the name suggests, they are designed to carry high axial loads for uses such as columns and piles.

Generally heavier than other steel sections, they are useful as supports for retaining walls and beam sections where headroom is of concern.

Parallel Flange Channels (PFC)

Parallel Flange Channels (PFC) are general purpose, hot rolled ‘C’ sections, often called a channel or a ‘C-section’.

The web of a PFC is out to one edge of the flange, changing the cross-section from an ‘I’ to a ‘C’ (hence the name). It is often used for columns, lintels above doors and as simple beams supporting floor joists.

Unequal Angles (UA) and Equal Angles (EA)

Both types of angles are L-shaped sections with a 90 degree corner that are perfect for use as lintels. An unequal angle is a metal angle section with two legs of unequal length, whereas the equal angle has two legs of the same length.

One leg of the ‘L’ can rest under brickwork, while the other resists the bending load over the window or door opening.