RSJ / Universal Beam (UB) Sizes in Ireland — Quick Guide, Uses & How to Order
Understand RSJs (UBs) vs UCs vs PFCs, see common sizes, and learn how to specify cutting, shot blasting and priming with Heiton Steel.
RSJ vs UB — what’s the difference?
In Ireland and the UK, “RSJ” is the traditional term often used by builders and homeowners. In modern steel catalogues, these are listed as Universal Beams (UB). Universal Columns (UC) have wider flanges relative to their depth and are typically used as vertical members. Parallel Flange Channel (PFC) is a C-shaped section used for lintels, framing and stiffeners.
Common UB / RSJ sizes (examples)
Below are popular, illustrative UB sizes (depth × width × kg/m). Availability can vary — we’ll confirm lead time and cutting options when you enquire.
| Designation | Depth × Width (mm) | Approx. kg/m | Typical uses |
|---|---|---|---|
| 152×89×16 UB | 152 × 89 | 16 | Small openings, domestic lintels (engineer-specified) |
| 178×102×19 UB | 178 × 102 | 19 | Domestic/Light commercial beams |
| 203×102×23 UB | 203 × 102 | 23 | Popular RSJ for internal wall removal (engineer-specified) |
| 254×146×31 UB | 254 × 146 | 31 | Medium spans, floor beams |
| 305×165×40 UB | 305 × 165 | 40 | Longer spans, structural framing |
| 356×171×51 UB | 356 × 171 | 51 | Heavier-duty beams and frames |
Note: Final beam size and grade must be specified by a qualified structural engineer.
Cutting, shot blasting & priming
- Computerised, conveyor-fed saw for accurate, repeatable cuts (mm precision)
- Splay cutting available (provide drawings/angles)
- In-house shot blasting and priming for a clean, protected finish
How to order your RSJ / UB
- Have your engineer’s beam specification (size, grade, length, any holes/plates).
- Tell us if you need splay cuts, shot blast/prime, and delivery date.
- We’ll confirm availability and provide a competitive quote with next-working-day options.
Find your nearest branch or contact us to get started.