HEM240 and HEM260 are European standard H-beam sections commonly supplied in S275JR and S355JR structural steel grades. They belong to the HEM series of the European HE family, the heaviest of the three flange series defined in EN 10365, and they are chosen where very high load capacity and stiffness are required in a compact section. The designation and the steel grade together define the geometry and the mechanical performance of the delivered beam.
What Does HEM Mean?
The HE family of European wide-flange sections comprises three series with the same nominal depth but different flange widths and thicknesses:
HEA: the light series, with the thinnest web and flanges.
HEB: the medium series, with thicker flanges than HEA.
HEM: the heavy series, with the thickest web and flanges and the greatest mass, giving the highest load capacity.
HEM therefore stands for the heavy flange series, not a lightweight section. The number in the designation, such as 240 in HEM240, represents the nominal section height in millimeters. In the HEM series, the flange width is typically slightly greater than the nominal depth, and the generous web and flange thicknesses give the section very high strength and stiffness in both bending and compression.
Section Characteristics of HEM240 and HEM260
The HEM240 and HEM260 sections are characterized by their wide, thick flanges and heavy web:
HEM240: nominal depth 240 mm, with a flange width slightly greater than the depth and thick web and flange elements, producing a section mass in the region of 150 kg per meter.
HEM260: nominal depth 260 mm, with a wider flange and thicker elements again, and a section mass in the region of 170 kg per meter.
Because the flanges are wide and thick, and the web height and thickness are proportioned for heavy loads, the sections effectively disperse stress, avoid local stress concentration, and improve the overall load-bearing efficiency of the structure. The exact dimensions, section properties, and tolerances are defined in EN 10365 and EN 10034, and the section properties tables of those standards should be used for design.
Steel Grades: S275JR and S355JR
HEM sections can be supplied in several structural steel grades. The two most common are defined in EN 10025-2:
S275JR: minimum yield strength 275 MPa for thicknesses up to 16 mm, with reduced values for thicker sections. It is a general structural grade with good weldability, suitable for conventional load-bearing structures.
S355JR: minimum yield strength 355 MPa for thicknesses up to 16 mm, with reduced values for thicker sections. It offers about 30 percent higher yield strength than S275JR and is selected where higher load capacity or lighter members are required.
The two grades differ mainly in yield strength and chemical composition, with S355JR containing slightly higher manganese and controlled carbon to achieve the higher strength while preserving weldability. Both are impact tested at 20 degrees Celsius with a minimum of 27 J, per the JR designation.
Why Choose a Heavy HEM Section
The HEM series is selected where the structural efficiency of a wide-flange section must be maximized:
High axial load capacity: the large cross-sectional area makes HEM sections excellent columns.
High bending stiffness: the wide, thick flanges provide large moment capacity for beams and girders.
Compact proportions: the section depth is moderate while the capacity is very high, which suits headroom-limited designs.
Stability: the wide flange geometry resists lateral-torsional buckling better than a narrow section of the same depth.
These characteristics make the HEM series a practical choice for heavily loaded columns and short-span, high-capacity beams where a lighter series would require an impractically large section.
Typical Applications
HEM240 and HEM260 sections in S275JR and S355JR are used in demanding structural roles:
Heavy columns in industrial buildings and high-rise frames, where the large section area carries high axial loads.
Crane runway girders and gantry supports, where heavy wheel loads and dynamic effects must be resisted.
Transfer structures and heavily loaded beams supporting equipment, storage, or upper floors.
Bridge substructures and heavy infrastructure frames.
Machine frames and heavy equipment bases in manufacturing facilities.
For the most heavily loaded members, the higher-strength S355JR grade is preferred because it increases the design capacity of the same section, while S275JR remains a cost-effective choice where the strength is adequate.
Frequently Asked Questions
What does HEM mean in a beam designation? HEM is the heavy series of the European HE wide-flange family, with the thickest web and flanges and the highest mass for a given nominal depth. HEA is the light series and HEB the medium series.
What does the number in HEM240 mean? The number represents the nominal section height in millimeters. HEM240 has a nominal depth of 240 mm and HEM260 a nominal depth of 260 mm.
What is the difference between S275JR and S355JR? S355JR has a higher minimum yield strength, 355 MPa compared with 275 MPa for S275JR in the thinner range, achieved by a slightly different composition, making it suitable for higher loads or lighter members.
Which standard governs HEM sections? The dimensions and section properties of HEM sections are defined in EN 10365, with manufacturing tolerances per EN 10034, and the steel grades are defined in EN 10025-2.
Are HEM sections weldable? Yes. Both S275JR and S355JR have good weldability, and the wide, parallel flanges simplify bolted and welded connections.
When should I choose a HEM section over HEA or HEB? Choose HEM where the load is very heavy and the section depth is limited, because the thick web and flanges provide the highest load capacity of the three series for the same nominal depth.