Joists - 89x89x19
A structural steel joist, also known as a Rolled Steel Joist (RSJ) is a solid, single piece of structural steel hot-rolled into an "I" or "H" shaped profile. It features a vertical central section (the web) that resists shearing forces, and horizontal top and bottom plates (the flanges) that prevent bending. Unlike modern Universal Beams (UBs) which have perfectly parallel flanges, classic RSJs feature slightly tapered, sloping inner flanges. They are incredibly strong, compact, and are the everyday "default" choice in UK residential construction for spanning wide openings, building extensions, and supporting load-bearing walls.
Nearby Sections
Dimensions
| Property | Value |
|---|---|
| kg/m | 19.5 |
| D mm | 88.9 |
| B mm | 88.9 |
| t mm | 9.5 |
| T mm | 9.9 |
| r1 mm | 11.1 |
| r2 mm | 3.2 |
| d mm | 44.2 |
| b/T | 4.49 |
| d/t | 4.65 |
| C mm | 7 |
| N mm | 46 |
| n mm | 24 |
| m2 | 0.476 |
| m2 | 24.4 |
Full sortable table: Dimensions table for this category
Section Properties
| Property | Value |
|---|---|
| Second Moment of Area (x-x) - cm4 | 307 |
| Second Moment of Area (y-y) - cm4 | 101 |
| Radius of Gyration (x-x) - cm | 3.51 |
| Radius of Gyration (y-y) - cm | 2.02 |
| Elastic Modulus (x-x) - cm3 | 69 |
| Elastic Modulus (y-y) - cm3 | 22.8 |
| Plastic Modulus (x-x) - cm3 | 82.7 |
| Plastic Modulus (y-y) - cm3 | 38 |
| Buckling Parameter - u | 0.83 |
| Torsional Index - x | 6.58 |
| Warping Constant - H dm6 | 0.00158 |
| Torsional Constant - J cm4 | 11.5 |
| Area of Section - A cm2 | 24.9 |
Full sortable table: Properties table for this category