IPN Beams

What is IPN beams?

IPN (I-Profil Normal, DIN 1025-1) is the classic European I-beam from the early twentieth century: the inside faces of the flanges slope at 14 %, the root radii are large, the web is thick and the flange narrow. The number is the depth in millimetres. Compared with the parallel-flange IPE that replaced it in the 1960s, an IPN of the same depth is 15–35 % heavier and has a noticeably higher web shear capacity and torsional stiffness — which is why it persists in machine bases, crane rails, trolley beams and any drawing older than the Eurocodes. The taper has a practical cost: bolted connections need taper washers (or the flange must be machined), and web cleats sit on a curved root. In Turkey and the CIS the section is still called NPI (normal profil I) and rolled by Kardemir and İçdaş in 80–600 mm. Grades are the same as for IPE — S235JR and S275JR from stock, S355J2 on order.

IPN dimensions and weight per metre

Grades and standards

Lengths, tolerances and stock

Lengths 6 and 12 m (+100/−0 mm); we stock IPN 80–300 in S235JR/S275JR at Dilovası and order 320–600 from the mill programme (1–3 weeks). Tolerances to EN 10024: depth ±2 mm (≤ 180) to ±4 mm (≥ 400), flange width ±2–3 mm, mass ±4–6 %. Cut to length ±5 mm standard, ±2 mm on request.

Cutting, drilling and galvanizing

Cut on band saws, straight or mitred; holes drilled through the tapered flange with taper-compensated washers supplied on request; notching and end-plate welding in the shop. Because of the flange taper we recommend drilling over punching. Hot-dip galvanizing to EN ISO 1461 (the thick root sections galvanize well) or shot-blast and primer.

Where it is used

• Renovation and extension of older industrial buildings
• Monorail trolley beams and light crane rails
• Machine bases and press foundations
• Lintels and door-frame beams in masonry
• Agricultural and workshop buildings in the Balkans and CIS
• Mining and tunnel supports (IPN arches)

IPN vs IPE

Same depth, different flanges: IPN tapers, IPE is parallel. IPE is 15–35 % lighter for the same bending capacity and bolts up cleanly, so every new design uses it — see IPE beams. Choose IPN when replacing like-for-like in an existing structure, when a trolley runs on the bottom flange (the taper centres the wheels), or when the specification explicitly says NPI / DIN 1025. Never mix the two in one line of beams — the depths are equal but the flange widths and stiffnesses differ.

Price

IPN shares the rolled-section price list with IPE — the band below is the month's indicative FOB Istanbul range per ton; larger sizes carry a small surcharge because of lower mill volume.

Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.

Export and packing

We pack IPN beams in strapped bundles of one size and one length (about 1–2 t per bundle for 6 m, 2–3 t for 12 m), tagged with size, grade and heat. 6 m bundles fill a 40' HC at 24–25 t; 12 m bundles are shipped on flat-racks or breakbulk from Derince. Tariff 7216.

Certificates

IPN beams ships with EN 10204 3.1 certificates matched to the bundle tags and the CE declaration of performance; 3.2 inspection certificates from a classification society are ordered per lot when the project requires them.

How to order

Send size (IPN/NPI number), grade, length or cut list, quantity and any drilling or coating; we confirm stock or mill date within one working day.

Standards

• EN 10365:2017 / DIN 1025-1 — dimensions
• EN 10024 — tolerances (tapered-flange I)
• EN 10025-2 — S235JR, S275JR, S355J2
• EN 10025-1 — CE marking

Grades

Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: S235JR · S275JR · S355J2