WT shapes are structural tees cut from wide-flange (W) beams: split a W-shape down the middle of the web and each half is a WT. The current AISC catalog lists 301 WT sections across 17 depth series, from the WT3X4.25 (4.25 lb/ft) up to the WT18X462.5 (462.5 lb/ft). The designation works exactly like a W-shape: WT5X11 means a tee with a nominal 5-inch depth weighing 11 pounds per foot — and it was cut from a W10X22.
Here's the full series chart, then everything you need to price and take off tees without second-guessing the schedule.
WT size and weight chart (all 301 sections)
Every WT series maps back to a parent W-shape family at exactly twice the nominal depth and twice the weight. The chart below covers all 17 series and every catalog weight in each one.
| Series | Cut from | Sections | Weight range (lb/ft) |
|---|---|---|---|
| WT2 | W4 | 1 | 6.5 |
| WT2.5 | W5 | 2 | 8 – 9.5 |
| WT3 | W6 | 7 | 4.25 – 12.5 |
| WT4 | W8 | 13 | 5 – 33.5 |
| WT5 | W10 | 18 | 6 – 56 |
| WT6 | W12 | 29 | 7 – 168 |
| WT7 | W14 | 38 | 11 – 436.5 |
| WT8 | W16 | 11 | 13 – 50 |
| WT9 | W18 | 23 | 17.5 – 155.5 |
| WT10.5 | W21 | 21 | 22 – 137.5 |
| WT12 | W24 | 21 | 27.5 – 185 |
| WT13.5 | W27 | 17 | 42 – 269.5 |
| WT15 | W30 | 16 | 45 – 195.5 |
| WT16.5 | W33 | 13 | 59 – 193.5 |
| WT18 | W36 | 41 | 67.5 – 462.5 |
| WT20 | W40 | 24 | 74.5 – 327.5 |
| WT22 | W44 | 6 | 115 – 204 |
And the full weight listing per series — every value below is a catalog WT designation (WT6X25 means the 25 lb/ft entry in the WT6 row):
| Series | Available weights (lb/ft) |
|---|---|
| WT2 | 6.5 |
| WT2.5 | 8, 9.5 |
| WT3 | 4.25, 4.5, 6, 7.5, 8, 10, 12.5 |
| WT4 | 5, 6.5, 7.5, 9, 10.5, 12, 14, 15.5, 17.5, 20, 24, 29, 33.5 |
| WT5 | 6, 7.5, 8.5, 9.5, 11, 13, 15, 16.5, 19.5, 22.5, 24.5, 27, 30, 34, 38.5, 44, 50, 56 |
| WT6 | 7, 8, 9.5, 11, 13, 15, 17.5, 20, 22.5, 25, 26.5, 29, 32.5, 36, 39.5, 43.5, 48, 53, 60, 68, 76, 85, 95, 105, 115, 126, 139.5, 152.5, 168 |
| WT7 | 11, 13, 15, 17, 19, 21.5, 24, 26.5, 30.5, 34, 37, 41, 45, 49.5, 54.5, 60, 66, 72.5, 79.5, 88, 96.5, 105.5, 116.5, 128.5, 141.5, 155.5, 171, 185, 199, 213, 227.5, 250, 275, 302.5, 332.5, 365, 404, 436.5 |
| WT8 | 13, 15.5, 18, 20, 22.5, 25, 28.5, 33.5, 38.5, 44.5, 50 |
| WT9 | 17.5, 20, 23, 25, 27.5, 30, 32.5, 35.5, 38, 43, 48.5, 53, 59.5, 65, 71.5, 79, 87.5, 96, 105.5, 117, 129, 141.5, 155.5 |
| WT10.5 | 22, 24, 25, 27.5, 28.5, 31, 34, 36.5, 41.5, 46.5, 50.5, 55.5, 61, 66, 73.5, 83, 91, 100.5, 111.5, 124, 137.5 |
| WT12 | 27.5, 31, 34, 38, 42, 47, 51.5, 52, 58.5, 65.5, 73, 81, 88, 96, 103.5, 114.5, 125, 139.5, 153, 167.5, 185 |
| WT13.5 | 42, 47, 51, 57, 64.5, 73, 80.5, 89, 97, 108.5, 117.5, 129, 140.5, 153.5, 168, 184, 269.5 |
| WT15 | 45, 49.5, 54, 58, 62, 66, 74, 86.5, 95.5, 105.5, 117.5, 130.5, 146, 163, 178.5, 195.5 |
| WT16.5 | 59, 65, 70.5, 76, 84.5, 100.5, 110.5, 120.5, 131.5, 145.5, 159, 177, 193.5 |
| WT18 | 67.5, 75, 80, 85, 91, 97, 105, 115, 115.5, 116, 122.5, 123.5, 128, 130, 131, 140, 141, 143, 150, 151, 159, 164, 165, 175, 179.5, 180.5, 193.5, 196.5, 197.5, 219.5, 220.5, 243.5, 263.5, 264.5, 325, 326, 361.5, 399, 401, 426.5, 462.5 |
| WT20 | 74.5, 83.5, 91.5, 99.5, 105.5, 107.5, 117.5, 124.5, 132, 138.5, 139, 147, 148.5, 162, 163.5, 165.5, 181, 186, 196, 198.5, 215.5, 251.5, 296.5, 327.5 |
| WT22 | 115, 131, 145, 167.5, 184, 204 |
Two rows worth a second look. WT7 runs 38 sections deep because it inherits the W14 column family — everything up to the super-heavy jumbo columns, which is how you end up with a "7-inch tee" that weighs 436.5 lb/ft with a flange thicker than most base plates. And WT18 carries 41 sections for the same reason: the W36 family is the workhorse girder line, so its tee offspring are everywhere in heavy truss chords.
What is a WT shape and how is it made?
A WT is not rolled as a tee. The mill (or more often the fabricator or service center) takes a standard wide-flange beam and flame-cuts or saws it longitudinally through the mid-depth of the web. One W-shape yields two identical tees, each with one flange and a stem that was half the parent's web.
That origin story explains everything about the catalog:
- Every WT has exactly one parent. WT5X11 exists because W10X22 exists. There is no WT size that doesn't correspond to a rolled W-shape.
- Dimensions are inherited. The flange width and flange thickness of a WT are identical to its parent's. The stem depth is half the parent's actual depth (minus the kerf, which the tables ignore), and the stem thickness equals the parent's web thickness.
- Availability follows the parent. If a W-shape is a slow-moving mill item, its tee will be a special-order item too. The common tees (WT4, WT5, WT6, WT7 in the light-to-mid weights) come from the most-rolled beam sizes, which is why they're cheap and everywhere.
The "nominal" depth caveat applies just like it does for W-shapes. A WT5X11 isn't exactly 5 inches deep — actual depth is about 5.09 inches, because its parent W10X22 is 10.17 inches deep, not 10. If you're checking clearances on a detail, pull the actual dimension from the AISC shape database, not the name.
How do you read a WT designation like WT5x11?
Same grammar as a wide-flange callout:
- WT — structural tee cut from a W-shape
- 5 — nominal depth in inches (stem tip to top of flange)
- 11 — weight in pounds per linear foot
So a WT5X11 that's 12'-6" long weighs 11 × 12.5 = 137.5 lbs. That's the entire weight calculation; the same math you'd run on a wide-flange beam works on its tee.
On drawings you'll see the multiplication sign written as X, x, or ×, and occasionally a fractional weight: WT9X17.5, WT7X21.5, WT13.5X269.5. The decimals are legitimate catalog sections, not typos — they're half of an odd-numbered parent weight (W18X35 → WT9X17.5). If a schedule shows "WT9X17" with no decimal, someone truncated it; there is no WT9X17 in the catalog, and it's worth an RFI before you price 40 of them.
WT vs ST vs MT: what's the difference?
All three are tees; the letter tells you the parent shape family.
| Designation | Cut from | Flange geometry | Where you'll see it |
|---|---|---|---|
| WT | W-shape (wide flange) | Wide, parallel-faced flange | 90%+ of tees on modern drawings |
| ST | S-shape (American Standard beam) | Narrow flange, ~17% sloped inner face | Legacy structures, crane rail details, renovation work |
| MT | M-shape (miscellaneous) | Light, narrow | Rare — light framing, some OEM/equipment work |
The AISC catalog carries far fewer of the other two — roughly 29 ST and 14 MT sections against 301 WTs — which matches how often you'll actually meet them. The practical trap is renovation work: a 1950s truss will call out STs (or "tees" with no prefix at all), and an ST9X35 is not interchangeable with a WT9X35.5. Different flange width, different stem, different section properties. Price what's drawn, and flag substitutions as an engineering question, not an estimating decision.
Where WTs show up: trusses, bracing, lintels
Knowing where tees live helps you know where to hunt for them on a drawing set:
- Truss chords and web members. The single biggest WT application. The open side of the tee makes a natural landing for gusset-free welded connections — double angles bolt to the stem, or web members weld straight to it. Roof trusses and long-span joist-girder substitutes are full of WT6s through WT9s.
- Bracing. WTs make clean brace members because the stem bolts directly to a gusset plate with no filler. Common in vertical bracing on one- and two-story industrial buildings.
- Lintels and shelf angles on steroids. Where a loose angle won't carry the masonry load, a WT with the stem up (or down) often does the job.
- Stiffening and reinforcement. Tees welded to existing beam flanges as strengthening on retrofit jobs.
- Hangers and posts. Light WT4/WT5 sections carrying mechanical loads, catwalks, and pipe supports.
On a typical commercial job, you'll find zero WTs on the framing plans and a dozen buried in the truss and bracing details. That distribution matters for takeoffs — more on that below.
Weight math: a WT weighs half its parent W-shape
This is the most useful sanity check in the tee world. Because a WT is literally half a W-shape:
| WT section | Parent W-shape | Check |
|---|---|---|
| WT5X11 | W10X22 | 11 = 22 ÷ 2 ✓ |
| WT6X13 | W12X26 | 13 = 26 ÷ 2 ✓ |
| WT9X17.5 | W18X35 | 17.5 = 35 ÷ 2 ✓ |
| WT12X31 | W24X62 | 31 = 62 ÷ 2 ✓ |
| WT18X462.5 | W36X925 | 462.5 = 925 ÷ 2 ✓ |
Three ways this earns its keep on a bid:
- Validating a suspicious callout. If a schedule lists a WT size, double it and check whether the parent W-shape exists. "WT8X21"? W16X42 isn't a catalog shape — the callout is wrong (probably WT8X20, from W16X40).
- Pricing when your supplier quotes the parent. Tees are often supplied as split beams. If the mill quote is on W12X26 and the fab splits it in-house, your material cost per foot of WT6X13 is half the beam cost plus the splitting labor — not a specialty-shape premium.
- Quick tonnage checks. A truss with 400 LF of WT7X24 is 9,600 lbs — the same steel as 200 LF of W14X48. If your tee tonnage looks wildly different from that kind of parent-shape gut check, recount.
Takeoff tip: WTs hide in truss details, not framing plans
The estimating problem with tees isn't identifying them — it's finding them. WT callouts cluster on detail sheets, truss elevations, and section cuts, which are exactly the pages that get skimmed at 9 p.m. the night before bid day. A truss elevation might show one labeled WT7X24 top chord and then note "TYP ALL TRUSSES" — and suddenly the difference between catching it and missing it is four tons of steel.
The other classic miss is the decimal weight. Manual takeoffs regularly record WT9X17.5 as WT9X17 or WT6X26.5 as WT6X26, and the downstream pricing lookup either fails or silently grabs the wrong section. Half-pound errors sound trivial until they're multiplied across every web member of every truss on the job.
This is a category where automated detection genuinely earns its keep: SteelFlo reads every sheet in the set — including the detail and truss pages humans skim — and boxes every WT, ST, and MT label it finds, with each callout validated against a database of 4,700+ sections across 6 standards. You review the boxes, confirm the counts, and the decimal weights come through intact. Detection plus human verification runs 95–99% accurate, and the tees on page 14 of the details get the same attention as the beams on the framing plan.
FAQ
How many WT sizes are there? The current AISC catalog lists 301 WT sections across 17 depth series, from WT2 through WT22. The largest series are WT18 (41 sections) and WT7 (38 sections).
What is the lightest and heaviest WT shape? Lightest: WT3X4.25 at 4.25 lb/ft. Heaviest: WT18X462.5 at 462.5 lb/ft, cut from the W36X925.
Is a WT5X11 the same as half a W10X22? Yes — dimensionally and by weight. One W10X22 split at mid-web yields two WT5X11 tees. Flange width and thickness are identical to the parent; the stem is half the parent's depth.
Can I substitute a WT for an ST of similar size? Not without engineering approval. They come from different parent families with different flange widths, stem thicknesses, and section properties. Price what's on the drawing and RFI any substitution.
Need to check a tee — or any of the other 4,700+ sections — while you're pricing? Look up any section's weight and properties in the free SteelFlo calculator, or browse the full shape listing on the shapes page. No signup, no spreadsheet hunting, and when you're ready to run a full drawing set, your first 3 takeoffs are free.