The main types of structural steel shapes are wide-flange (W) beams, standard I-beams (S), H-piles (HP), channels (C and MC), angles (L), tees (WT), hollow structural sections (HSS), pipe, and plate and bar. In Canada each one is named with a letter and metric dimensions, such as W200x27, C200x17, L102x102x9.5 or HSS 102x102x6.4. The W-shape does most of the work in beams and columns; the others handle posts, lintels, bracing, framing and connections.
This guide walks through each shape, how it is named, and where it gets used.
Structural steel shapes at a glance
| Shape | Letter | How it's named | Example | Typical uses |
|---|---|---|---|---|
| Wide-flange | W | Nominal depth (mm) x mass (kg/m) | W200x27 | Beams, columns, girders |
| Standard I-beam | S | Depth x mass | S200x27 | Older buildings, hoist and trolley beams |
| Bearing pile | HP | Depth x mass | HP200x53 | Driven piles, some heavy columns |
| Channel | C, MC | Depth x mass | C200x17 | Framing, ledgers, stair stringers, light beams |
| Angle | L | Leg x leg x thickness (mm) | L102x102x9.5 | Lintels, bracing, clip angles, trim |
| Tee | WT | Depth x mass (cut from a W) | WT cut from W200x27 | Truss chords, hangers, stiffeners |
| Hollow structural section | HSS | Outside dimensions x wall (mm) | HSS 102x102x6.4 | Posts, columns, frames, bracing |
| Pipe | Pipe | Nominal size and schedule | NPS 3 standard weight | Columns, bollards, handrails |
| Plate and flat bar | PL, FB | Thickness x width (mm) | PL 12 x 200 | Base plates, cap plates, connection plates |
The first group (W, S, HP, C, L, WT) are hot-rolled shapes: formed by passing hot steel through shaped rolls at the mill. HSS is usually formed from flat steel into a tube and welded along a seam. Plate is rolled flat.
The I-shaped family: W, S, HP and M
All four look like an I or an H in cross-section: two flanges joined by a web.
- W (wide-flange) is the standard beam and column shape. The inside faces of the flanges are parallel, which makes bolting and welding simple. Sizes run from W100 up to W1100 in the CISC tables, and within each depth group the flanges get thicker and often wider as the mass goes up.
- S (standard I-beam, or American Standard beam) has narrower flanges with sloped inside faces. It is the classic "I-beam" profile, still found under some hoists and trolleys and common in older buildings.
- HP (bearing pile) has flanges and web of the same thickness and flanges about as wide as the section is deep. It is made to be driven into the ground, but heavy HP sections also turn up as columns.
- M (miscellaneous) shapes are light I-shaped sections that don't fit the W or S series. They are uncommon and availability is limited.
People say "I-beam" and "H-beam" in everyday speech, but on a Canadian drawing almost all of these will be W-shapes. Our guide on I-beam vs W-beam vs H-beam sorts out the names.
Welded wide-flange (WWF) sections are a Canadian series built up from three plates welded together. They are named like W-shapes and are used where a member needs to be larger or heavier than the rolled range offers.
Channels: C and MC
A channel has a web and two flanges that point the same way, giving a squared C. Standard channels (C) have tapered inside flange faces; miscellaneous channels (MC) cover sizes and proportions outside the standard series.
- Named by nominal depth and mass, like W-shapes: a C200x17 is about 203 mm deep and weighs about 17 kg/m.
- Sizes in the common Canadian range run from C75 to C380. Our C-channel size chart lists them with dimensions and mass.
- Used for framing around openings, ledgers bolted to walls, stair stringers, equipment frames, bracing, and light beams where the load can be applied through the web.
Because a channel is not symmetrical about its web, a load applied to the flange tends to twist it. That is fine for framing, ledgers and paired channels, but it limits channels as stand-alone beams. Back-to-back channels are a common way around that.
Note that cold-formed channels (light-gauge C and Z sections bent from thin sheet, used for studs, girts and purlins) are a different product designed to a different standard, CSA S136, not the hot-rolled channels described here.
Angles: L
An angle has two legs at right angles. Equal-leg angles have both legs the same; unequal-leg angles have one longer leg.
Angles are named by the two leg lengths and the thickness, all in millimetres, with the imperial equivalent in inches. A few common sizes, from the AISC Shapes Database metric listing:
| Metric | Imperial | Mass (kg/m) |
|---|---|---|
| L51x51x6.4 | 2 x 2 x 1/4 | 4.7 |
| L76x76x6.4 | 3 x 3 x 1/4 | 7.3 |
| L89x89x6.4 | 3-1/2 x 3-1/2 x 1/4 | 8.6 |
| L102x102x9.5 | 4 x 4 x 3/8 | 14.6 |
| L127x89x7.9 | 5 x 3-1/2 x 5/16 | 12.9 |
| L152x102x9.5 | 6 x 4 x 3/8 | 18.2 |
| L152x152x9.5 | 6 x 6 x 3/8 | 22.2 |
Angles are the usual shape for masonry lintels over windows and doors, and they are everywhere in connections (clip angles), bracing, shelf angles, frames and edge trim. On an unequal angle used as a lintel, which leg is vertical matters a lot; see angle iron as a lintel.
Tees: WT
A tee is made by cutting a W-shape lengthwise through the web, giving two T-shaped pieces. A WT is named by its depth and mass, so a WT cut from a W200x27 is about half the depth and half the mass of the beam it came from.
Tees are used for truss chords, hanger and connection pieces, stiffeners and some lintel and edge details. They are less common in houses.
HSS and pipe: the tube shapes
Hollow structural sections come in three forms:
- Square (for example HSS 102x102x6.4): the usual basement and deck post, and a common column.
- Rectangular (for example HSS 203x102x6.4): frames, lintels, beams with low torsion demands and members that need more strength in one direction.
- Round (for example a 168.3 mm diameter tube with a 6.4 mm wall): columns, exposed architectural work, bollards.
HSS is named by outside dimensions and wall thickness, not mass. Its closed shape gives it high torsional stiffness and makes it efficient as a column. Canadian HSS is commonly CSA G40.21 350W. The full size range is in our HSS sizes chart.
Pipe looks like round HSS but is named by nominal pipe size and schedule or weight class (standard, extra strong), following piping conventions. It is used for columns, bollards and railings. Lally columns are a familiar residential example.
Plate and bar
Plate is flat steel named by thickness and width (and length), for example PL 12 x 200. It becomes base plates, cap plates, gussets, shear tabs, stiffeners and built-up members, and nearly every fabricated piece of steel includes some.
Flat bar is narrow plate rolled to width. Round and square bar are solid sections used for anchor rods, hangers, railings and miscellaneous work.
Weights for plate follow directly from thickness: 7.85 kg per square metre for every millimetre of thickness. Our structural steel size and weight chart puts plate alongside the rolled shapes.
Which shape for which job
| Job | Shape usually chosen | Why |
|---|---|---|
| Floor or roof beam | W | Most bending strength and stiffness per kilogram |
| Basement or deck post | Square HSS, or pipe | Equal stiffness both ways, compact, easy plates |
| Heavy column with many beam connections | W | Open flanges make bolted connections simple |
| Lintel over a masonry opening | L (angle) | Supports brick on one leg, easy to set |
| Ledger or framing around an opening | C (channel) | Flat back bolts to walls, flanges frame members |
| Bracing | L, HSS or WT | Light, easy to connect |
| Base, cap and connection plates | Plate | Cut and drilled to suit |
| Hoist or trolley beam | S or W | Both are used; the engineer checks the flange for wheel loads |
The final choice is the designer's or engineer's. Shape, size and grade are all part of the design, and substituting one shape for another (a channel for a W, or a round post for a square one) needs their approval.
Shapes cut and fabricated to your drawings
We supply and fabricate beams, posts, plates, channels and angle lintels, cut, drilled and welded to the shop drawings we prepare in-house, with CWB certified shop welding. Send your drawings for a free take-off and quote, or see the steel products we supply.
Frequently asked questions
What are the main types of structural steel shapes?
The main hot-rolled shapes are wide-flange (W) beams, standard I-beams (S), bearing piles (HP), channels (C and MC), angles (L) and tees (WT). Hollow structural sections (HSS) and pipe are the tube shapes, and plate and bar complete the set.
What is the most common structural steel shape?
The wide-flange (W) shape. It is used for most beams and many columns because its wide, parallel flanges put the steel where it does the most work in bending.
How are structural steel shapes named in Canada?
By a letter for the shape followed by metric dimensions. W, S, HP and C shapes are named by nominal depth in mm and mass in kg/m (W200x27). Angles and HSS are named by their outside dimensions and thickness in mm (L102x102x9.5, HSS 102x102x6.4).
What is the difference between a channel and an angle?
A channel (C) has a web and two flanges on the same side, forming a squared C. An angle (L) has just two legs at right angles. Channels are used for framing, ledgers and light beams; angles for lintels, bracing, clips and edge trim.
