# Taper Flange Beams TFB

> Source page: [https://steelinfo.au/taper-flange-beams/](https://steelinfo.au/taper-flange-beams/)

AS/NZS 3679.1

Small hot-rolled I-beams with tapered (8°) flanges, used for lintels, light framing and trailers. Dimensions, section properties, AS 4100 capacities and free DXF drawings for all 2 sizes.

Taper flange beams (TFB) are small hot-rolled I-sections whose flanges taper at 8°. Only the 100TFB and 125TFB remain in common use, typically for lintels, light framing, trailer and truck bodies, and monorail beams for light hoists, where trolleys with tapered wheels run on the sloping bottom flange.

The flange thickness t_f is quoted at the middle of the flange outstand. Use tapered washers for bolts through the sloping flange faces.

**Select any section in the table** to open its page, with a dimensioned drawing, all section properties, AS 4100 capacities and a free **DXF download** for your CAD software.

| Designation | Mass (kg/m) | d (mm) | b_f (mm) | t_f (mm) | t_w (mm) | A_g (mm²) | I_x (10⁶mm⁴) | Z_x (10³mm³) | S_x (10³mm³) | I_y (10⁶mm⁴) | r_y (mm) | J (10³mm⁴) | φM_sx (kNm) | φN_s (kN) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [125TFB](https://steelinfo.au/taper-flange-beams/125tfb/) | 13.1 | 125 | 65 | 8.5 | 5.0 | 1675 | 4.34 | 69.4 | 80.3 | 0.337 | 14.2 | 31.1 | 23.1 | 482 |
| [100TFB](https://steelinfo.au/taper-flange-beams/100tfb/) | 7.20 | 100 | 45 | 6.0 | 4.0 | 917 | 1.46 | 29.2 | 34.1 | 0.0794 | 9.3 | 8.36 | 9.8 | 264 |

[All TFB DXFs (.zip)](https://steelinfo.au/downloads/taper-flange-beams-dxf.zip) · [Table as CSV](https://steelinfo.au/downloads/taper-flange-beams.csv) · [Compare sections](https://steelinfo.au/compare/)

## Frequently asked questions

**Is a TFB the same as a small UB?**

No. TFB flanges slope at 8° on their inside faces and are thicker at the root, while UB flanges are parallel. Use tapered washers on the sloping faces.

**Which TFB sizes are available?**

The 100TFB (7.2 kg/m) and 125TFB (13.1 kg/m) are the sizes still in common use.

## Relevant Australian Standards

- **AS/NZS 3679.1:2016** Structural steel – Part 1: Hot-rolled bars and sections — Specifies chemical composition, mechanical properties and tolerances for hot-rolled universal beams and columns, channels, angles, flats and bars in Grades 300 and 350.
- **AS 4100:2020** Steel structures — The Australian design Standard for steel members and connections. Covers section classification (Section 5), member moment capacity including lateral-torsional buckling (5.6), shear (5.11), axial compression (Section 6), tension (Section 7) and combined actions (Section 8).
- **AS/NZS 5131:2016** Structural steelwork – Fabrication and erection — Fabrication, erection, tolerances, inspection and construction categories (CC1–CC4) for structural steelwork.

See all [Australian Standards for structural steel](https://steelinfo.au/australian-standards/).

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From SteelInfo (https://steelinfo.au/taper-flange-beams/), 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.