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HE 800 B vs H-800x300x17x34

HE 800 B is an HE section from the European (Continental) range; H-800x300x17x34 is the closest equivalent in the European (Continental) range. H-800x300x17x34 carries more bending: 10680 cm³ of plastic modulus against 10200 cm³, 4.5% more. They weigh essentially the same, 262 kg/m and 267 kg/m. Both are about 808 mm deep, so either fits the same construction zone.

Section properties side by side. Bold marks the more favourable value where one is.
PropertyHE 800 B
HE
H-800x300x17x34
MB & MC
Difference
Mass262 kg/m267 kg/m-1.9%
Depth800 mm816 mm-2.0%
Width300 mm303 mm-1.0%
Web thickness17.5 mm17 mm+2.9%
Flange thickness33 mm34 mm-2.9%
Area334 cm²340 cm²-1.8%
Second moment, major (Iy)359,000 cm⁴383,600 cm⁴-6.4%
Plastic modulus, major (Wpl,y)10,200 cm³10,680 cm³-4.5%
Elastic modulus, major (Wel,y)8,980 cm³9,402 cm³-4.5%
Second moment, minor (Iz)14,900 cm⁴15,820 cm⁴-5.8%
Plastic modulus, minor (Wpl,z)1,550 cm³1,625 cm³-4.6%
Radius of gyration, minor (iz)6.68 cm6.82 cm-2.1%
Torsion constant (It)959 cm⁴1,003 cm⁴-4.4%

HE 800 B to EN 10365 · Continental Steel; H-800x300x17x34 to Continental Steel. Difference is expressed relative to H-800x300x17x34.

How to choose between them

On stiffness, H-800x300x17x34 has the larger second moment of area: 383,600 cm⁴ against 359,000 cm⁴, a difference of 6.4%. This matters more often than the strength comparison, because on normal floor spans deflection rather than bending capacity sets the beam size - so if the two are close on modulus but apart on inertia, the stiffer one is usually the better answer even when it is not the stronger one.

Measured as bending capacity per kilogram of steel, H-800x300x17x34 is the more efficient section: 40.0 against 38.9 cm³ per kg/m, 2.7% better. Over a floor of repeated beams that difference is real tonnage, though it is often outweighed by whichever section the fabricator can actually source.

In short, H-800x300x17x34 is the stronger section and HE 800 B is the lighter one; where those are the same section, it is the clear choice, and where they are not, decide on whether your design is governed by capacity or by tonnage.

Common questions

H-800x300x17x34 is the stronger of the two in bending, with a plastic modulus of 10680 cm³ against 10200 cm³ - 4.5% more. At the same steel grade that translates directly into moment capacity, since M_pl,Rd = W_pl x f_y / gamma_M0.

Neither meaningfully: HE 800 B is 262 kg/m and H-800x300x17x34 is 267 kg/m. On a tonnage basis they cost the same.

Structurally it is the closest equivalent we hold: H-800x300x17x34 gives 10680 cm³ of plastic modulus and 383,600 cm⁴ of inertia against 10200 cm³ and 359,000 cm⁴. Re-check deflection and the connection details before swapping, since the flange and web thicknesses differ.

H-800x300x17x34, with a second moment of area of 383,600 cm⁴ against 359,000 cm⁴ (6.4% more). Deflection under a uniform load goes as 5wL⁴/384EI, so it is inversely proportional to I - on a span where the deflection limit governs rather than strength, this is the number that decides the section.

Related comparisons

W 33X169 vs HE 800 BW 30X173 vs HE 800 B
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