EN 10365 · EN 10056 · EN 10219 · Đakovo
Section properties of rolled sections for load-bearing steel structures: mass per metre, moment of inertia Iy and elastic section modulus Wel,y to EN 10365 and DIN 1026-1, with cross-sections drawn to scale and selection criteria according to the role of the element in the structure.
Rolled and cold-formed sections
EN 10365
The basic section of hall construction. A deep, narrow cross-section gives the greatest section modulus per unit of mass when the load acts in one plane, so it is used for the rafters and columns of standard frames.
18 sizes · depth 80–600 mm · 6–122.4 kg/m
EN 10365
The flange width equals the section depth. Considerably stiffer about the weak axis than an IPE of the same depth — chosen for columns that can buckle in both planes.
11 sizes · depth 96–290 mm · 16.7–88.3 kg/m
EN 10365
The same overall dimensions as HEA, thicker material. Used where the section depth must not increase: crane runways, heavily loaded columns, floor structures.
10 sizes · depth 100–300 mm · 20.4–117 kg/m
DIN 1026-1
An open cross-section with a flat back that seats against another element. Frames for door and window openings, trims, equipment supports.
6 sizes · depth 100–200 mm · 10.6–25.3 kg/m
EN 10056
The simplest section. In a hall it works as a bracing diagonal, as a connection for the secondary structure and as a substructure for cladding.
EN 10219
A closed cross-section, equally stiff in both planes and resistant to torsion. Lattice girders, bracing, canopies and exposed elements where appearance also matters.
EN 1993-1-3
A thin wall, cold-formed instead of hot-rolled. It overlaps at the support so that two spans behave as a continuous beam — which is why it carries the roof covering between the frames.
Nominal size 300 · same scale
Three sections of nominal designation 300, drawn side by side at the same scale. The comparison shows the relationship between mass and section modulus at the same nominal size. A point that is often overlooked: HEA 300 has an actual section depth of 290 mm — the designation is the nominal size, not the depth.
IPE 300
actual depth 300 mm · width 150 mm
The lightest and the cheapest. A narrow flange means low stiffness about the weak axis — it calls for lateral restraint.
HEA 300
actual depth 290 mm · width 300 mm
For 46 kg/m more it gives a flange twice as wide. It is chosen when the column can buckle in both planes.
HEB 300
actual depth 300 mm · width 300 mm
The same overall dimensions as HEA, thicker material. It is taken when the section depth must not grow.
Choose a series, then a section
Selecting a row draws the cross-section to scale. The same scale applies within each series, so the relative slenderness of the sections is comparable at a glance.
IPE 270
Beams, rafters and columns of the standard hall
A deep, narrow cross-section — the most section modulus per kilogram of steel when the load acts in one plane. That is why IPE is the default choice for the rafters and columns of halls. Modeco's standard hall 10×30×5 m stands on IPE 330 columns and IPE 240 rafters with a haunch.
| Section | h × b mm | tw / tf mm | mass kg/m | Iy cm⁴ | Wel,y cm³ |
|---|---|---|---|---|---|
| IPE 80 | 80 × 46 | 3.8 / 5.2 | 6 | 80 | 20 |
| IPE 100 | 100 × 55 | 4.1 / 5.7 | 8.1 | 171 | 34.2 |
| IPE 120 | 120 × 64 | 4.4 / 6.3 | 10.4 | 318 | 53 |
| IPE 140 | 140 × 73 | 4.7 / 6.9 | 12.9 | 541 | 77.3 |
| IPE 160 | 160 × 82 | 5 / 7.4 | 15.8 | 869 | 109 |
| IPE 180 | 180 × 91 | 5.3 / 8 | 18.8 | 1,317 | 146 |
| IPE 200 | 200 × 100 | 5.6 / 8.5 | 22.4 | 1,943 | 194 |
| IPE 220 | 220 × 110 | 5.9 / 9.2 | 26.2 | 2,772 | 252 |
| IPE 240 | 240 × 120 | 6.2 / 9.8 | 30.7 | 3,892 | 324 |
| IPE 270 | 270 × 135 | 6.6 / 10.2 | 36.1 | 5,790 | 429 |
| IPE 300 | 300 × 150 | 7.1 / 10.7 | 42.2 | 8,356 | 557 |
| IPE 330 | 330 × 160 | 7.5 / 11.5 | 49.1 | 11,770 | 713 |
| IPE 360 | 360 × 170 | 8 / 12.7 | 57.1 | 16,270 | 904 |
| IPE 400 | 400 × 180 | 8.6 / 13.5 | 66.3 | 23,130 | 1156 |
| IPE 450 | 450 × 190 | 9.4 / 14.6 | 77.6 | 33,740 | 1500 |
| IPE 500 | 500 × 200 | 10.2 / 16 | 90.7 | 48,200 | 1928 |
| IPE 550 | 550 × 210 | 11.1 / 17.2 | 105.5 | 67,120 | 2441 |
| IPE 600 | 600 × 220 | 12 / 19 | 122.4 | 92,080 | 3069 |
The values are standard section properties (EN 10365), not a Modeco price list. Which section carries your structure is determined by the structural calculation of an authorised engineer according to the loads at your site (snow, wind, ground).
Primary and secondary structure
The section is chosen according to the role of the element. The positions listed are taken from Modeco's standard hall 10 × 30 × 5 m — the same one from the public calculation.
Column
IPE 330
Transfers the roof and wind load into the foundation. The section depth grows with the height of the hall and the span.
Rafter (roof beam)
IPE 240 with a haunch
The haunch — a thickening at the joint — adds section modulus exactly where the moment is greatest, instead of enlarging the whole section.
Purlin
Z-section, cold-formed
Carries the roof covering between the frames. The overlap at the support makes a row of spans a continuous beam.
Bracing
Round tie rod or L / SHS
Takes the horizontal wind forces and holds the geometry of the hall during erection and afterwards.
Selection criteria
01
Bending capacity is measured by W el,y, and it grows faster than the mass, because the moment of inertia depends on the square of the distance of the material from the centroid. IPE 400 is 35 % heavier than IPE 330, but carries 62 % more. Across the whole series: IPE 600 gives 7.5 times more capacity per kilogram than IPE 80. That is why one goes to a deeper section before going to thicker material.
02
The moment in the frame is not the same along its length — it is greatest at the joint. A thickening only there (the haunch) is cheaper than enlarging the whole rafter. That is why Modeco's IPE 240 rafter carries a span that would otherwise call for a larger section.
03
S355 carries about 50 % more than S235 for the same cross-section, so it reduces mass. But it costs more per kilogram and is more demanding to weld — the calculation is done project by project, not by rule.
EN 10025-2
The designation S355J2+N carries four pieces of information: the intended use of the steel, the yield strength, the toughness in the cold and the delivery condition. The difference between seemingly identical quotations is often exactly here.
S
Structural steel
The letter states the intended use. S is for structural — load-bearing structural steel to EN 10025-2. There are other groups (e.g. E for mechanical engineering), but in hall construction it is almost always S.
355
Yield strength in N/mm²
The nominal yield strength for the smallest material thickness. S235 yields at 235 N/mm², S355 at 355. S355 carries about 50 % more for the same cross-section — but that value falls as the material gets thicker, so the calculation uses the actual value for that thickness.
J2
Toughness in the cold
An impact energy of 27 J: JR at +20 °C, J0 at 0 °C, J2 at −20 °C. For a structure standing outdoors in continental Croatia this is not a small matter but the question of how the steel behaves in January.
+N
Delivery condition
+AR means as-rolled, +N normalising. Normalised material has a more uniform structure and behaves more predictably when welding thicker sections.
Production process
Between the rolled section and the erected structure there are five steps. Each is carried out to a standard and each is documented, so the execution is verifiable.
01
EN 1090-2
The workshop drawing, lengths and openings. An error here travels through the entire structure.
02
EN 1090-2
Edges, grooves, end plates and the haunch — the preparation determines what weld is possible at all.
03
EN ISO 3834-2
A certified welding quality system: procedures, welders and supervision, not just the finished weld.
04
ISO 12944
The dry film thickness is chosen according to the corrosivity category of the environment and the required service life.
05
EN 1090-2 · EXC
Tolerances, sequence and tightening of the connections. A structure is proven by documentation, not by impression.
Modeco's plant is certified for execution class EXC3 to EN 1090-2, with welding to EN ISO 3834-2. What the execution class means for the price and the documentation is set out on the steel structures page.
Questions and answers
IPE has a narrow flange and a deep web — the most load capacity per kilogram when the load acts in one plane. HEA and HEB have a flange width roughly equal to the section depth, so they are considerably stiffer about the weak axis. HEB has the same overall dimensions as HEA but a thicker web and flange, therefore greater load capacity at greater mass. For example: IPE 300 has a mass of 42.2 kg/m and W el,y 557 cm³, HEA 300 has 88.3 kg/m and 1,260 cm³, and HEB 300 has 117 kg/m and 1,678 cm³.
An IPE 330 has a mass of 49.1 kg per metre of length, a cross-section of 330 × 160 mm, a web thickness of 7.5 mm and a flange thickness of 11.5 mm, a moment of inertia I y of 11,770 cm⁴ and an elastic section modulus W el,y of 713 cm³ (EN 10365). The mass follows directly from the cross-sectional area of 6,261 mm² and the density of steel of 7,850 kg/m³.
The roof covering is carried by the purlin — in prefabricated halls most often a cold-formed Z-section that overlaps at the support, so that a row of spans behaves as a continuous beam. The purlins transfer the load to the rafters (roof beams), and these to the columns. In Modeco's standard hall 10 × 30 × 5 m the rafters are IPE 240 with a haunch and the columns IPE 330.
The number is the nominal yield strength in N/mm²: S235 yields at 235 N/mm², S355 at 355 N/mm². S355 carries about 50 % more for the same cross-section, so it reduces the mass of the structure, but it costs more per kilogram and is more demanding to weld. The choice is always a calculation of mass against price, not a rule.
The values are standard section properties to EN 10365 (IPE, HEA, HEB) and DIN 1026-1 (UPN). Every row is checked against two physical equalities that a correct cross-section must satisfy: the mass must follow from the cross-sectional area and the density of steel of 7,850 kg/m³, and the elastic section modulus from the moment of inertia and the section depth. The check runs automatically on every change to the page.
No. An HEA 300 has an actual section depth of 290 mm and a width of 300 mm. On HEA sections the designation is the nominal size, not the actual depth — an HEB 300 is exactly 300 mm deep, and an IPE 300 is also 300 mm. The 10 mm difference on the HEA regularly comes as a surprise when an assembly is set out by depth.
The designation carries four pieces of information to EN 10025-2. S denotes structural steel. The number 355 is the nominal yield strength in N/mm² for the smallest material thickness. J2 means an impact energy of 27 J at −20 °C (JR is at +20 °C, J0 at 0 °C). +N denotes the normalised delivery condition, as opposed to +AR, which means as-rolled.
Because the moment of inertia depends on the square of the distance of the material from the centroid of the cross-section, while the mass grows only linearly. The section modulus per kilogram of mass therefore grows with the depth of the section: an IPE 600 gives about 5.9 times more section modulus per kilogram than an IPE 100 (25.1 against 4.2 cm³ per kg/m). Increasing the section depth is almost always cheaper than increasing the material thickness.
Modeco designs, manufactures and erects steel structures in execution class EXC3 to EN 1090-2, with welding to EN ISO 3834-2. For requirements for individual sections or semi-finished products, send a list of positions with lengths and steel grade — we report availability and lead time.
Lengths, sections and steel grade — we report availability, mass and lead time. For a complete structure we prepare a calculation and a quotation with separate items.