UPN vs UPE Channel: Flange Shape, Mass, Connections and Uses, with Section Tables

Steel channels are a common section in steel frames, and the Ahan Assa catalog carries two European types: UPN and UPE. They look alike at first glance, but their flange shape, mass per metre and ease of connection differ. This guide sets out the difference between UPN and UPE channels using the section data in the Ahan Assa catalog, so you can check exactly what the drawings call for and what to specify when you order.

What a channel is, and where UPN and UPE are defined

A channel is a hot-rolled U-shaped section: a web with two flanges on one side. The nominal dimensions and masses of both UPN and UPE are set by EN 10365. The EVS listing describes the standard as specifying "the nominal dimensions and masses of the hot rolled steel channels, I and H sections", and names UPE and UPN among the channels it covers. The same listing shows a 2026 edition replacing the 2017 edition from 15 July 2026; our catalog dimensions reference the 2017 edition.

The number after the designation is the section depth in millimetres, so a UPN 160 is 160 mm deep. All channels in the Ahan Assa catalog are grade S235JR to EN 10365.

The key difference: tapered or parallel flanges

• UPN: the inner face of each flange is tapered, so the flange gets thinner towards its tip. Our catalog lists an 8% flange slope for every UPN size.
• UPE: in the words of Projectmaterials, UPE channels "share the same U-shaped cross-section as UPN profiles, but their flanges run parallel rather than tapering."

That small difference affects three things: mass per metre at a given depth, how bolted and welded connections are made, and where each section tends to be used.

Dimensions and mass at equal depth

Dimensions in mm, nominal mass in kg/m, from the Ahan Assa catalog:

At every depth the UPE flange is 5 mm wider and its web thinner, and across these sizes the UPE is roughly 7.5–10.5% lighter per metre. Lighter is not automatically better or weaker: Projectmaterials notes that a UPN can deliver slightly higher bending efficiency than a UPE of the same depth, depending on the load case and support conditions. The choice is the structural engineer's.

Our UPN range also continues to larger depths: UPN 220 (29.4 kg/m), UPN 240 (33.2), UPN 260 (37.9), UPN 280 (41.8) and UPN 300 (46.2).

Flange shape and connections

According to Projectmaterials, the flat, uniform flange surfaces of a UPE simplify bolted and welded connections. On a UPN, a flat washer seated on the sloping inner flange face bears on one edge only. The usual remedy is a square taper washer to DIN 434: fastener supplier BelMetric notes that the inside slope of channel flanges is commonly 8% and that these washers act as shims to give the bolt or nut a parallel bearing surface. If your drawings show bolts through UPN flanges, add taper washers to the fixings list.

Where each is typically used

Projectmaterials summarises common practice as follows:

• UPN: most often in industrial and civil work such as supports, equipment bases and bracing frames.
• UPE: in projects with extensive bolted or welded flange connections, including building frames.

This is a tendency rather than a rule; the designer selects the section on each project. If channels work alongside angles in bracing or trusses, see our guide to steel angle uses in structures.

What to specify before ordering

• State the section type in full: UPN 160 or UPE 160, not just "channel 160".
• Take the size from the drawings: our catalog covers UPN 80–300 and UPE 80–200; see the UPN channel and UPE channel pages for the full lists.
• Estimate the weight: length × mass per metre, e.g. 12 m of UPN 160 is about 225.6 kg and 12 m of UPE 160 about 204 kg. Nominal mass is for estimating; delivered weight is what the weighbridge shows.
• Order unit: kilograms, tonnes or metres.
• Grade and standard: S235JR to EN 10365; ask before ordering if the drawings call for another grade.
• No substitution without the designer's approval.

To request a quotation for a specific quantity, use our contact form.

Summary

UPN and UPE are both hot-rolled U-sections to EN 10365. The UPN has tapered flanges (8% in our catalog) and a thicker web; the UPE has wider, parallel flanges and a thinner web, which makes it lighter at the same depth and easier to connect through the flanges, while bolting through a UPN flange calls for DIN 434 taper washers. The designer decides which section fits; the buyer's job is to read the type and size in full from the drawings, estimate the weight, and never swap one for the other without approval.