HEM Beam: Dimensions & Weight

Quick Reference

HEM beams are the heaviest European wide flange beams (I-shaped), with thicker flanges than HEA/HEB. Used for heavy-duty applications: multi-story buildings, bridges, industrial facilities. Standards: EN 10034 (dimensions), EN 10025 (grades S275, S355). Range: HEM 100 to HEM 1000. Best for long spans requiring maximum load capacity with minimal intermediate supports.

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Need a printable version? Download the Structural Steel Beams Chart for HEM, HEA, HEB, IPE, IPN dimensions and weights.

HEM Steel Beams (“M” Sections)

What Are HEM Steel Beams?

HEM beams are the heaviest series in the European wide-flange beam family, alongside HEA and HEB. For a given size designation (e.g., HEM 300), the HEM has the same nominal depth and flange width as HEA/HEB 300, but with significantly thicker flanges and web. The result is a beam that weighs roughly 50-70% more than the HEB equivalent but delivers substantially more bending and axial capacity.

HEM steel beam

HEM beams are specified when the loads or spans exceed what HEB can handle efficiently - typically as transfer beams carrying multiple floors, primary columns in multi-story buildings, crane girders, bridge main beams, and heavy industrial portal frames. They’re also used where the beam depth is constrained (low headroom) but the load is high: the thicker flanges of HEM provide extra capacity without increasing the overall depth.

The “M” designation originally comes from the French “Moyenne” or German “Mittel” in early European classification, though today it simply represents the heavy series. In some older references you’ll see them called “Continental wide flange” sections.

HEM vs HEA/HEB: Quick Comparison

To put the difference in concrete numbers, here’s a comparison at size 300:

Property	HEA 300	HEB 300	HEM 300
Depth	290 mm	300 mm	340 mm
Flange width	300 mm	300 mm	310 mm
Flange thickness	14 mm	19 mm	39 mm
Web thickness	8.5 mm	11 mm	21 mm
Weight	88.3 kg/m	117 kg/m	238 kg/m
Section modulus Wx	1260 cm³	1680 cm³	4078 cm³

The HEM 300 weighs about twice the HEB 300 but offers 2.4x the section modulus. Where depth is not the constraint, you could achieve similar capacity with a larger HEB - but when headroom is tight or you need maximum stiffness at a given depth, HEM is the answer.

The design hierarchy is simple: start with HEA for preliminary sizing. If it’s not enough, step up to HEB. If HEB isn’t enough, go to HEM. If HEM isn’t enough, you’re looking at built-up plate girders or trusses.

Specifications and Material Grades

HEM beams are governed by the same European standards as HEA/HEB:

Standard	Scope
EN 10365	Dimensions and masses for the full HEM range (HEM 100 to HEM 1000)
EN 10034	Tolerances on shape and dimensions
EN 10025	Steel grades and mechanical properties

The standard material grades are the same as for HEA/HEB beams:

Grade	Yield (MPa)	Tensile (MPa)	Impact	Use
S235JR	235	360-510	27J at +20°C	Secondary members, light framing
S275JR	275	410-560	27J at +20°C	General building frames
S355J2	355	470-630	27J at -20°C	Primary structure, bridges, industrial
S355K2	355	470-630	40J at -20°C	Cold-climate applications
S460M	460	540-720	27J at -20°C	Bridges, cranes, high-performance structures

S355J2 is the default for heavy structural applications. S460M (thermomechanically rolled) is specified for projects where reducing steel weight matters - bridges and long-span structures - though it requires more attention to welding procedures due to the higher strength.

Dimensions & Weights HEM Steel Beams

The dimensions and weight of HEM steel beams vary significantly across the range, catering to a variety of structural needs. The HEM series offers some of the largest and heaviest H-sections available, making them suitable for major construction projects requiring high load-bearing capacity and long spans. The following table provides a generalized overview of the dimensions and weights for a selection of HEM steel beams. Please note, for precise specifications, always refer to the latest standards or manufacturer’s details.

HEM Dimensions & Weights by Size

Beam Size	Depth (mm)	Width of Flange (mm)	Thickness of Web (mm)	Thickness of Flange (mm)	Weight (kg/m)
HEM 100	120	106	12	20	41.8
HEM 120	140	126	12.5	21	52.1
HEM 140	160	146	13	22	63.2
HEM 160	180	166	14	23	76.2
HEM 180	200	186	14.5	24	88.9
HEM 200	220	206	15	25	103
HEM 220	240	226	15.5	26	117
HEM 240	270	248	18	32	167
HEM 260	290	268	18	32.5	172
HEM 280	310	288	18.5	33	177
HEM 300	340	310	21	39	244
HEM 320	359	309	21	40	251
HEM 340	377	309	21	40	256
HEM 360	395	308	21	40	262
HEM 400	432	307	21	40	291
HEM 450	478	307	21	40	320
HEM 500	524	306	21	40	349
HEM 550	572	306	21	40	377
HEM 600	620	305	21	40	405
HEM 650	668	305	21	40	434
HEM 700	716	304	21	40	461
HEM 800	814	303	21	40	520
HEM 900	910	302	21	40	582
HEM 1000	1008	302	21	40	642

HEM Size Chart (EN 10034/10025): Mechanical Properties by Size

HEM Dimensions & Weights

HEM Sizes EN 10034/10025 1/2	Sizes in mm	Cross Section cm²	Modulus Section cm³
HEM Beam Size	h	b	s
HEM 100	120	106	12
HEM 120	140	126	12.5
HEM 140	160	146	13
HEM 160	180	166	14
HEM 180	200	186	14.5
HEM 200	220	206	15
HEM 220	240	226	15.5
HEM 240	270	248	18
HEM 260	290	268	18
HEM 280	310	288	18.5
HEM 300	340	310	21
HEM 320	359	309	21
HEM 340	377	309	21
HEM 360	395	308	21
HEM 400	432	307	21
HEM 450	478	307	21
HEM 500	524	306	21
HEM 550	572	306	21
HEM 600	620	305	21
HEM 650	668	305	21
HEM 700	716	304	21
HEM 800	814	303	21
HEM 900	910	302	21
HEM 1000	1008	302	21

HEM Beam Selection Criteria

Choosing HEM steel beams for a construction project involves considering several key factors that make these beams particularly suitable for certain applications. HEM beams, with their wide flanges and substantial depth, offer unique advantages:

Selection Criteria	Description
High Load-Bearing Capacity	Designed to bear heavy loads without additional support columns; large cross-sectional area and reliable structure
Long Spans	Greater depth allows longer spans between supports; ideal for auditoriums, warehouses, and industrial buildings requiring open spaces
Durability & Structural Integrity	Substantial web and flange material withstands environmental stresses, vibrations, and factors that compromise less reliable beam types
Design Flexibility	Versatile for standard and innovative architectural designs; suitable for building frames, bridges, heavy machinery support
Aesthetic Appeal	Visually substantial and professional look; aligns with modern design trends favoring clean lines and open spaces
Cost-Efficiency	Long-term savings through reduced need for additional supports and maintenance; fewer materials needed for long spans
Structural Safety	Reliable support against loads; reduces risk of structural failure

Conclusion

The decision to use HEM steel beams is driven by the need for high strength, long spans, durability, and versatility in construction projects. While the initial cost might be higher compared to other beam types, the long-term benefits of using HEM beams, including structural integrity, design flexibility, and cost savings, often justify the investment. Engineers and architects choose HEM beams for challenging projects where these factors are critical to the success and longevity of the structure.