UPN channel table: dimensions, weight and properties

Updated October 29, 2026  ·  Indumor

Carry a full bucket in one hand and you walk bent toward it. A loaded UPN channel does something similar. Its shear center, the point a load would have to pass through for the section not to rotate, lies outside the section, behind the web. When the load comes down through the web, the channel bends and twists as well.

Below are the dimensions, weight per meter and section properties of UPN 50 to 400 to DIN 1026-1, with the distance e from the back to the centroid, plus a weight calculator.

UPN channel table: dimensions and weight per meter

Section properties for design

The UPN seen from the design office and from the fitting table

From the design side, the first issue is that bucket twist. A UPN purlin loaded through the web rotates unless something holds it, so it gets braced or used in pairs. Two UPNs back to back, or toe to toe and welded into a box, move the shear center to the middle and multiply the weak-axis inertia, which for a single UPN 200 is thirteen times smaller than the strong one. Many shed columns are built that way, and the steel building tool in our engineering Suite checks them.

The second is the e value in the table. It locates the centroid from the back and is needed for any compound section, from a box to a channel welded to a plate. For I sections, see the IPN beam table.

On light roofs, purlins are usually cold-formed C sections, lighter for the same span. The UPN is kept for heavier loads or where something has to be welded onto a solid member.

From the fitting table, the flat back is what everyone appreciates. It sits fully against a plate, a wall or another member, and gets welded or bolted without shims. That is why the UPN is the section for equipment skid frames, for stair stringers and for gate frames.

It has its quirks. Weld one side along its length and the bead pulls the channel into a banana. Happens all the time. Spreading the heat with short, alternating runs prevents it, as we explain in welding distortion. And since the flanges slope inward at 8 %, or 5 % on UPN 320 to 400, bolts through them take a taper washer of the same slope; the 8 % one is in DIN 434.

In Argentina UPN channels follow IRAM-IAS U 500-509 and are sold mostly in grade F-24, in 12 m bars; UPN 50 to 120 also come in 6 m, and distributors mostly stock UPN 80 to 240. Rolling tolerances are set by EN 10279.

Need a frame, a stair or a structure built from UPN? Tell us what it is, with dimensions or a sketch, and Indumor will quote the parts cut, welded and painted.

← See all technical tables