Channel sections

What the stock form specifies

ArcelorMittal's 2023 catalogue lists UPE 200 at 22.8 kg/m and UPN 200 at 25.3 kg/m. One 6.000 m length gives 136.8 kg or 151.8 kg, respectively, before attachments, coatings or tolerances. Check the flange and web geometry, section properties and design requirements before substituting. ArcelorMittal UPE and UPN tables

A channel has a web and two flanges projecting to the same side, leaving an open cross-section. The designation describes a section family and size; it does not independently establish material strength, toughness, corrosion protection or a permissible load. This reference concentrates on steel channels. A similarly shaped aluminum extrusion or stainless fabricated channel needs its own material and product requirements.

ArcelorMittal's product range separates UPE and PFC parallel-flange channels, UPN tapered-flange channels, and American C and MC series. Its table identifies dimensional standards, tolerance standards and available steel-grade families in separate columns. Preserve that separation when ordering or comparing stock. ArcelorMittal, channel product range

A useful item description includes the complete series/size, material grade and edition, manufacturing route, length, finish and certification. “200 channel” leaves several of those unresolved.

Designation families and units

ArcelorMittal associates UPE, UPN and PFC dimensions with EN 10365 and their tolerances with EN 10279. Its American C/MC rows reference ASTM A6/A6M. These references describe the listed products; do not apply them indiscriminately to a custom folded channel. The web page has no verified technical revision date. ArcelorMittal, product range

AISC's Naming Convention for Structural Steel Products for Use in EDI, June 25, 2001, gives customary forms C<nominal depth, in.>X<nominal weight, lb/ft> and MC<nominal depth, in.>X<nominal weight, lb/ft>. It separately defines metric depth/mass designations. Thus C15X33.9 describes a nominal 15-inch depth and 33.9 lb/ft, not a 33.9-inch flange. Keep the original designation and unit system alongside any converted dimensions. AISC naming convention, section 3

Manufacturing route and geometry

A hot-rolled channel and a cold-formed C-section are different product families even when their envelopes look similar. Metsec describes its proprietary purlins and side rails as lightweight, cold-rolled galvanized sections, including C profiles, supplied pre-punched and cut to length. It provides system-specific software, accessories and technical details supported by component and full-scale testing. This is a system example, not a general capacity statement for all C-shaped stock. No issue date was verified on the cited page. Voestalpine Metsec, purlins and side rails

For a formed or fabricated replacement, obtain the actual drawing: web depth, flange width, thickness, corner radii, lips if present, holes and their locations. Do not transfer rolled-section properties to a bent-sheet approximation with sharp corners. Likewise, distinguish the uncoated base-metal thickness from a measurement that includes coatings when the governing specification makes that distinction.

Parallel and tapered flange faces also create different mating geometry. Check the bearing surface and fastener arrangement against the actual cross-section rather than assuming a flat bracket or washer fits every channel series.

Reading section tables

Keep these quantities distinct:

• Dimensions and mass: depth, width, web/flange thickness, radii and mass per length.
• Bending properties: second moment of area and elastic/plastic section moduli, with their stated axes.
• Stability properties: radii of gyration, torsion and warping constants where provided.
• Detailing geometry: fillet clearances and connection dimensions, which are not interchangeable with simplified design dimensions.

Record the table edition and its axis sketch. Area uses squared length units, section modulus cubed units and second moment of area fourth-power units; a millimeter/centimeter mismatch can overwhelm a comparison. Preserve both the original value and unit when importing data.

DIN's public record identifies EN 10279:2000, German publication March 2000, as the hot-rolled-channel standard for tolerances on shape, dimensions and mass. A nominal table dimension is therefore not a promise of exact measured size. Read the applicable tolerance provisions before defining incoming inspection or machining allowance. DIN Media, DIN EN 10279:2000-03

Bounded geometry and mass example

ArcelorMittal's Sections and Merchant Bars sales programme, retrieved as the V2023-5 PDF with printed copyright 2023, lists the following nominal dimensions. This is the actual cited edition, not the newer year appearing in some discovery links. ArcelorMittal catalogue, UPE/UPN tables

Loading, restraint and connections

An open channel's load path needs explicit attention. FHWA's LRFD for Highway Bridge Superstructures Reference Manual, based on the 2014 AASHTO specifications with interim revisions through 2015, explains that a channel's shear center differs from its centroid and lies outside the section in the illustrated case. Loading away from the shear center introduces torsion; open sections can also warp under torsion. These mechanics explain a limitation, rather than establishing the current design rules for a particular project. FHWA reference manual, section 6.4.8.1

A selection check should therefore establish orientation, load application point, unbraced length, restraint and connection stiffness before comparing capacity. A strong-axis bending property alone does not resolve twist, lateral stability, local behavior or a connection limit. Two channels placed back-to-back also need a designed connection and spacing arrangement; placing them together does not automatically create a fully composite member.

For substitution, compare the section drawing, material, loads, supports, environment and fabrication requirements.

Related reference

Stock forms and dimensions