H-beams and I-beams are both steel sections made of two flanges joined by a web. The difference is proportion: an I-beam has flanges much narrower than its depth, while an H-beam has flanges about as wide as it is deep, so its cross-section looks like the letter H.
H-Beam vs I-Beam at a Glance
| I-beam | H-beam | |
|---|---|---|
| AISC shapes | S shapes (American Standard beams); narrow W shapes are also often called I-beams | W shapes with flange width close to depth, and HP bearing piles |
| Flange width vs depth | Narrow, e.g. S8x23: 8 in deep, 4.17 in flange | About equal, e.g. W8x31: 8 in deep, 8 in flange |
| Inner flange faces | Sloped on S shapes | Parallel |
| Commonly used for | Beams spanning between supports | Columns and piles |
8-Inch Sections Compared
Real AISC values for four sections that are all about 8 in deep:
| Shape | Weight (lb/ft) | Depth (in) | Flange width (in) | Ix (in⁴) | Iy (in⁴) |
|---|---|---|---|---|---|
| S8x23 | 23 | 8 | 4.17 | 64.7 | 4.27 |
| W8x18 | 18 | 8.14 | 5.25 | 61.9 | 7.97 |
| W8x31 | 31 | 8 | 8 | 110 | 37.1 |
| HP8x36 | 36 | 8.02 | 8.16 | 119 | 40.3 |
Ix measures stiffness about the strong axis and Iy about the weak axis. The H-shaped W8x31 and HP8x36 have far higher Iy than the narrow I-shaped S8x23 and W8x18.
Which Is Stronger?
Neither shape is stronger in general. The right section depends on the load, span, bracing and whether the member acts as a beam or a column, and that must be checked by a licensed structural engineer.
Related: H-beam sizes chart, I-beam sizes chart, what is an I-beam.
Source: AISC Shapes Database v16.0, consistent with the AISC Steel Construction Manual, 16th Edition. Last updated: September 2026. Reference information only, not engineering advice. Disclaimer.