IPE and HE are both European I-sections to EN 10365, but they are built for different jobs. The difference is the flange: IPE is narrow and deep, HE is wide. That single geometric choice cascades into every design decision.
IPE: efficient in pure bending
The IPE puts its material high and low, far from the neutral axis, so it gives a lot of major-axis bending resistance per kilogram. For a simply supported floor beam carrying gravity load, with the slab or restraint holding the compression flange, the IPE is usually the lightest - and therefore cheapest - solution. Compare sizes on the IPE reference tables.
Its weakness is the narrow flange: low minor-axis stiffness and a higher tendency to lateral-torsional buckling when the compression flange is unrestrained. An IPE spanning unrestrained over a long bay can lose a lot of its on-paper capacity to LTB.
HE: stocky, stable, and a better column
The wide flange of the HEA (lighter) and HEB (heavier) families buys two things: far more minor-axis stiffness, and much better resistance to lateral-torsional and column buckling. That makes HE the natural choice for columns, for beams that are laterally unrestrained, and where a shallow but strong member is needed for headroom. See the HE reference tables.
The trade-off is mass. For the same major-axis bending strength a HE generally weighs more than an IPE - you pay for the stability you may not need.
Deciding on numbers
| Situation | Usually pick |
|---|---|
| Restrained floor beam, gravity load | IPE (lightest) |
| Column, axial + bending | HE (buckling resistance) |
| Long unrestrained span | HE, or IPE + restraints |
| Limited structural depth | HE (strength at shallow depth) |
The honest rule: if the compression flange is held, IPE saves weight; if it is free, or the member is a column, HE earns its extra mass. Pull the exact properties from the steel catalogue and check the candidate size for both moment and buckling before you commit.