Structural Shapes — Family Index
Family-index reference for rolled, welded, and cold-formed structural shapes used in steel building, bridge, industrial, and tower construction. Covers North American (AISC) designations, European (EN) profiles, and ancillary plate, sheet, bar, and cold-formed product. All dimensions in SI primary with US-customary in parentheses.
1. At a glance — global designation catalog
US AISC standard shapes (rolled hot-rolled per ASTM A6/A6M; properties tabulated in AISC Steel Construction Manual 16th ed. 2023):
| Designation | Family | Typical material | Use |
|---|---|---|---|
| W | Wide-flange beam (I-section, parallel flanges) | ASTM A992 (Fy = 345 MPa / 50 ksi) | Beams, columns — the workhorse |
| S | American Standard I-beam (sloped inner flange) | A36 (Fy = 250 MPa / 36 ksi) | Legacy; rare new spec |
| HP | H-pile (square section: bf ≈ d, equal flange/web thickness) | A572 Gr.50 (Fy = 345 MPa) | Driven foundation piles |
| M | Misc. light I-shape | A36 / A572 | Light framing, lintels |
| C | American Standard channel (sloped flange) | A36 / A572 | Purlins, edge beams, struts |
| MC | Misc. channel (heavier, deeper than C) | A36 / A572 | Stair stringers, ship/car framing |
| L | Angle, equal-leg or unequal-leg | A36 / A572 Gr.50 | Bracing, cleats, lintels |
| WT / MT / ST | Structural tee, split from W / M / S | Same as parent shape | Truss chords, gusset elements |
| HSS | Hollow Structural Section (square, rectangular, round) | A500 Gr.B/C, A1085 | Columns, braces, exposed framing |
| Pipe | Round pipe, Std / X-Strong / XX-Strong | A53 Gr.B, A106 Gr.B | Columns, handrails, pipe rack |
| FB | Flat bar | A36 | Stiffeners, gussets, infill |
| Round bar | Solid round | A36 / A572 / A108 (CRS) | Rods, tie-rods, pins |
European standard shapes (per EN 10025, dimensions per EN 10365 with property values per ArcelorMittal / Tata / Salzgitter section tables):
| Designation | Family | Typical material | Use |
|---|---|---|---|
| IPE | I-beam, parallel flanges, constant flange/web ratio | S235JR / S355JR (EN 10025-2) | Beams (Europe equivalent of W-light) |
| HEA | H-section, light (b ≈ d, thin flange/web) | S235 / S275 / S355 | Columns, beams |
| HEB | H-section, standard (b = d square section ≤ HE300) | S355JR | Columns — primary choice |
| HEM | H-section, heavy (thick flange/web) | S355 / S460 | Heavy columns, transfer members |
| HEAA | H-section, extra-light (thinner than HEA) | S235 / S355 | Light columns where weight critical |
| UPN | Channel, sloped flange (older series) | S235 / S275 | Legacy channels |
| UPE | Channel, parallel flange | S235 / S355 | Modern channel pick |
| L | Angle, equal or unequal leg | S235 / S355 | Bracing, cleats |
| CHS | Circular hollow section | S235J2H / S355J2H (EN 10210 hot-formed; EN 10219 cold-formed) | Columns, trusses, masts |
| RHS | Rectangular hollow section | EN 10210 / EN 10219 | Columns, beams, frames |
| SHS | Square hollow section | EN 10210 / EN 10219 | Columns, braces |
2. W-shapes — wide-flange (AISC)
Naming convention. W{nominal depth in}×{weight lb/ft} in US-customary; W{nominal depth mm}×{mass kg/m} in SI. Example: W14×90 (US) = W360×134 (SI metric designation) — nominal 360 mm depth, 134 kg/m. Nominal depth differs slightly from actual depth d; the suffix locks the cross-section.
Range. W4 to W44 (US) — i.e., 100 mm to 1100 mm nominal depth. Within each depth, multiple weight options (e.g., W14 family runs from W14×22 to W14×730).
Representative members and key properties (A992 Fy = 345 MPa / 50 ksi; properties per AISC Manual 16th ed., Table 1-1):
| Designation (US / SI) | d mm (in) | bf mm (in) | tf mm (in) | tw mm (in) | A mm² (in²) | Ix 10⁶ mm⁴ (in⁴) | Sx 10³ mm³ (in³) | rx mm (in) | Iy 10⁶ mm⁴ (in⁴) | Sy 10³ mm³ (in³) | ry mm (in) | Zx 10³ mm³ (in³) | Zy 10³ mm³ (in³) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| W8×31 / W200×46.1 | 203 (8.00) | 203 (8.00) | 11.0 (0.435) | 7.24 (0.285) | 5870 (9.13) | 45.4 (110) | 446 (27.5) | 88.1 (3.47) | 15.4 (37.1) | 152 (9.27) | 51.3 (2.02) | 503 (30.4) | 232 (14.1) |
| W10×49 / W250×73 | 253 (9.98) | 254 (10.0) | 14.2 (0.560) | 8.64 (0.340) | 9290 (14.4) | 113 (272) | 894 (54.6) | 110 (4.35) | 38.7 (93.4) | 305 (18.7) | 64.5 (2.54) | 1010 (60.4) | 467 (28.3) |
| W12×65 / W310×97 | 308 (12.1) | 305 (12.0) | 15.4 (0.605) | 9.91 (0.390) | 12300 (19.1) | 222 (533) | 1440 (87.9) | 134 (5.28) | 73.2 (174) | 480 (29.1) | 77.2 (3.02) | 1610 (96.8) | 730 (44.1) |
| W12×96 / W310×143 | 323 (12.7) | 308 (12.2) | 22.1 (0.900) | 14.0 (0.550) | 18200 (28.2) | 347 (833) | 2150 (131) | 138 (5.44) | 109 (270) | 705 (44.4) | 77.7 (3.09) | 2390 (147) | 1080 (67.5) |
| W14×90 / W360×134 | 356 (14.0) | 369 (14.5) | 18.0 (0.710) | 11.2 (0.440) | 17100 (26.5) | 416 (999) | 2330 (143) | 156 (6.14) | 151 (362) | 819 (49.9) | 94.0 (3.70) | 2620 (157) | 1250 (75.6) |
| W14×120 / W360×179 | 368 (14.5) | 372 (14.7) | 23.9 (0.940) | 15.0 (0.590) | 22800 (35.3) | 574 (1380) | 3120 (190) | 159 (6.24) | 207 (495) | 1110 (67.5) | 95.3 (3.74) | 3490 (212) | 1700 (102) |
| W16×26 / W410×38.8 | 399 (15.7) | 140 (5.50) | 8.76 (0.345) | 6.40 (0.250) | 4940 (7.68) | 124 (301) | 624 (38.4) | 159 (6.26) | 4.00 (9.59) | 56.7 (3.49) | 28.4 (1.12) | 720 (44.2) | 89.5 (5.48) |
| W18×35 / W460×52 | 450 (17.7) | 152 (6.00) | 10.8 (0.425) | 7.62 (0.300) | 6650 (10.3) | 213 (510) | 957 (57.6) | 179 (7.04) | 6.41 (15.3) | 84.5 (5.12) | 31.0 (1.22) | 1100 (66.5) | 134 (8.06) |
| W21×50 / W530×74 | 528 (20.8) | 166 (6.53) | 13.6 (0.535) | 9.65 (0.380) | 9480 (14.7) | 410 (984) | 1560 (94.5) | 208 (8.18) | 10.4 (24.9) | 125 (7.64) | 33.0 (1.30) | 1800 (110) | 200 (12.2) |
| W24×55 / W610×82 | 599 (23.6) | 178 (7.01) | 12.8 (0.505) | 10.0 (0.395) | 10500 (16.2) | 559 (1350) | 1860 (114) | 230 (9.11) | 12.1 (29.1) | 137 (8.30) | 33.8 (1.34) | 2150 (134) | 220 (13.3) |
| W24×84 / W610×125 | 612 (24.1) | 229 (9.02) | 19.6 (0.770) | 12.4 (0.470) | 15900 (24.7) | 988 (2370) | 3230 (196) | 249 (9.79) | 94.5 (227) | 825 (50.4) | 77.0 (3.04) | 3690 (224) | 1290 (78.4) |
| W27×84 / W690×125 | 678 (26.7) | 254 (10.0) | 16.3 (0.640) | 11.7 (0.460) | 15900 (24.8) | 1180 (2850) | 3490 (213) | 273 (10.7) | 44.5 (107) | 351 (21.2) | 52.8 (2.07) | 3970 (244) | 545 (33.2) |
| W30×99 / W760×147 | 753 (29.7) | 266 (10.5) | 17.0 (0.670) | 13.2 (0.520) | 18800 (29.1) | 1690 (4060) | 4490 (269) | 300 (11.7) | 53.7 (128) | 403 (24.5) | 53.3 (2.10) | 5160 (312) | 634 (38.6) |
| W36×150 / W920×223 | 911 (35.9) | 304 (12.0) | 23.9 (0.940) | 16.0 (0.625) | 28500 (44.2) | 3700 (9040) | 8130 (504) | 359 (14.3) | 112 (270) | 738 (45.1) | 62.7 (2.47) | 9420 (581) | 1190 (74.0) |
Additional properties of interest: J (torsional constant, mm⁴), Cw (warping constant, mm⁶), ho (distance between flange centroids, mm). Required for LTB checks per AISC 360 Chapter F.
The “go-to” picks (US engineering practice):
- W8×31, W10×49, W12×65, W12×96, W14×90, W14×120 — typical office/industrial column inventory
- W16×26, W18×35, W21×50, W24×55 — light-to-mid floor beams (composite or non-composite)
- W24×84, W27×84, W30×99 — heavier floor / transfer / long-span beams
- W36×150 and up — long-span / heavy-load transfer girders, bridge stringers
W4 to W6 ranges exist (W4×13, W6×9, W6×16, W6×25) for very-light bracing or short posts but are uncommon outside special details. W40 and W44 ranges (W40×149 to W44×335) appear in plate-girder-rivaling rolled sections for long bridge spans and heavy industrial framing.
3. S, HP, M shapes (AISC)
S — American Standard I-beam. Older profile; sloped inner flange (typically 16⅔% slope). Largely supplanted by W for new construction. Common members: S3×5.7, S6×12.5, S12×31.8, S15×42.9, S20×66, S24×80. Still specified for crane runways, rail, and some retrofit work where the steep flange suits specific connections. Material: typically A36.
HP — H-pile. Wide-flange optimized for driving as a foundation pile: equal flange and web thickness, square-ish cross-section (bf ≈ d), heavy web to survive driving stresses. Range HP8×36 to HP18×204. Common picks: HP10×42, HP12×53, HP12×74, HP14×73, HP14×102, HP14×117, HP14×177. Material: ASTM A572 Gr.50 (Fy = 345 MPa) or A992. Specified per AASHTO LRFD / AISC for pile foundations. Driven open-ended; develops capacity through skin friction + end bearing.
M — Misc. light I-shape. Light, mill-specific rolled sections that don’t fit W, S, or HP categories. Rare in design specification (use W instead). Example: M4×6, M5×18.9, M6×4.4, M8×6.5, M12.5×11.6. Often used for cold-formed substitutes, light lintels, or as bar-joist chords.
4. C and MC channels (AISC)
C — American Standard channel. Sloped flange (16⅔% inner slope). Range C3×4.1 to C15×50. Common members:
| Designation | d mm (in) | bf mm (in) | Mass kg/m (lb/ft) | A mm² (in²) | Ix 10⁶ mm⁴ (in⁴) | Sx 10³ mm³ (in³) |
|---|---|---|---|---|---|---|
| C3×4.1 | 76.2 (3.00) | 35.8 (1.41) | 6.10 (4.10) | 778 (1.21) | 0.700 (1.66) | 18.3 (1.10) |
| C4×5.4 | 102 (4.00) | 41.1 (1.58) | 8.04 (5.40) | 1020 (1.59) | 1.580 (3.85) | 30.9 (1.93) |
| C6×10.5 | 152 (6.00) | 51.7 (2.03) | 15.6 (10.5) | 1990 (3.09) | 6.20 (15.2) | 81.8 (5.06) |
| C8×11.5 | 203 (8.00) | 57.4 (2.26) | 17.1 (11.5) | 2180 (3.38) | 13.5 (32.6) | 134 (8.14) |
| C9×20 | 229 (9.00) | 68.6 (2.65) | 29.8 (20.0) | 3790 (5.88) | 25.3 (60.9) | 222 (13.5) |
| C12×30 | 305 (12.0) | 80.5 (3.17) | 44.6 (30.0) | 5680 (8.81) | 67.4 (162) | 442 (27.0) |
| C15×50 | 381 (15.0) | 94.5 (3.72) | 74.4 (50.0) | 9480 (14.7) | 169 (404) | 887 (53.8) |
MC — Misc. channel. Heavier-than-C variants; deeper webs or wider flanges. Range MC3×7.1 to MC18×58. Common picks: MC6×18, MC8×22.8, MC10×33.6, MC12×50, MC18×42.7. Used where C is insufficient (stair stringers, ship-type framing, heavy lintels).
Channels in pairs. “2C” or “2MC back-to-back” or “toe-to-toe” assemblies are common as truss chords or struts. Connect with batten plates or lacing per AISC 360 §E6.
5. Angles L (AISC)
Naming. L{long-leg}×{short-leg}×{thickness} in inches (US) or L{long}×{short}×{t} in mm (SI). E.g., L4×3×1/4 (102×76×6.4 mm).
Equal-leg angles. Range L2×2×⅛ to L8×8×1⅛. Common picks: L2×2×¼, L3×3×¼, L3×3×⅜, L4×4×¼, L4×4×⅜, L4×4×½, L5×5×⅜, L6×6×⅜, L6×6×½, L8×8×½, L8×8×1.
Unequal-leg angles. Range L3×2×¼ to L9×4×⅝ (and bigger): L3×2×¼, L4×3×¼, L5×3×¼, L5×3½×⅜, L6×4×⅜, L7×4×½, L8×6×½, L8×6×1, L9×4×⅝.
Properties of interest. Ax, Iy (about both legs), and especially rz (minimum radius of gyration about the principal Z-Z axis, governs slenderness in compression bracing). Also α (angle between geometric and principal axes). AISC Manual Table 1-7 / 1-8 gives full properties.
Material. ASTM A36 historically; A572 Gr.50 increasingly common for matched-yield bracing.
Use cases. Concentric/eccentric braces, hanger / cleat connections, lintels (single or double L), built-up sections (2L back-to-back gusseted, 2L star), light truss webs, equipment supports.
6. WT / MT / ST tees (AISC)
Tees are cut longitudinally from W, M, or S beams. Designation = source family with first letter “T”: WT split from W, MT split from M, ST split from S. The nominal depth of the tee is roughly half the parent. Example: WT5×30 is cut from a W10×60. WT9×35.5 from W18×71.
Range. WT2×6.5 to WT22×167 (full range mirrors all W cuts).
Material. Inherits from parent (typically A992 for WT).
Properties. Asymmetric about the neutral axis (one flange + stem). Ix differs significantly above vs. below NA. y_bar (distance to NA from flange face) tabulated in AISC Manual Table 1-8.
Use cases.
- Truss chords (top: compression, with stem down; bottom: tension, with stem up) — flange forms continuous load path, stem provides for web member connections
- Hanger connections where a flange must transfer load to bolt-attached supports
- Gusset / kicker plates where a stem-as-leg geometry is convenient
- Edge members in steel deck or stair landings
7. HSS — Hollow Structural Sections
ASTM A500 Gr.B / Gr.C — cold-formed welded, the standard for North American HSS through 2010s. Gr.B: Fy = 290 MPa (42 ksi) round, 317 MPa (46 ksi) square/rect. Gr.C: Fy = 317 MPa (46 ksi) round, 345 MPa (50 ksi) square/rect.
ASTM A1085 (introduced 2013) — tighter wall-thickness tolerance (full nominal t used in design, no 0.93 reduction factor), Fy = 345 MPa (50 ksi) all shapes, higher CVN toughness. Preferred for new design where supplier offers it.
Naming.
- Square:
HSS{a}×{a}×{t}— e.g., HSS6×6×¼ (152×152×6.4 mm) - Rectangular:
HSS{a}×{b}×{t}— e.g., HSS10×6×⅜ (254×152×9.5 mm) - Round:
HSS{OD}×{t}— e.g., HSS6.625×0.250 (168×6.4 mm)
Common square HSS.
| HSS | t mm (in) | Mass kg/m (lb/ft) | A mm² (in²) | Ix 10⁶ mm⁴ (in⁴) | Sx 10³ mm³ (in³) |
|---|---|---|---|---|---|
| HSS3×3×¼ | 6.35 (0.250) | 12.8 (8.62) | 1630 (2.53) | 1.83 (4.40) | 47.0 (2.94) |
| HSS4×4×¼ | 6.35 (0.250) | 17.7 (11.9) | 2260 (3.50) | 4.62 (11.1) | 91.5 (5.55) |
| HSS5×5×⅜ | 9.53 (0.375) | 31.3 (21.1) | 3990 (6.18) | 13.4 (32.3) | 213 (12.9) |
| HSS6×6×¼ | 6.35 (0.250) | 27.5 (18.5) | 3500 (5.43) | 17.2 (41.3) | 226 (13.8) |
| HSS6×6×⅜ | 9.53 (0.375) | 40.2 (27.0) | 5110 (7.93) | 24.0 (57.6) | 314 (19.2) |
| HSS8×8×½ | 12.7 (0.500) | 70.7 (47.5) | 9000 (14.0) | 76.6 (184) | 753 (45.9) |
| HSS10×10×½ | 12.7 (0.500) | 89.4 (60.1) | 11400 (17.6) | 157 (377) | 1230 (76.3) |
| HSS12×12×⅝ | 15.9 (0.625) | 134 (90.4) | 17000 (26.4) | 357 (859) | 2230 (139) |
Common rectangular HSS. HSS6×4×¼, HSS8×4×¼, HSS8×6×⅜, HSS10×6×⅜, HSS12×4×⅜, HSS12×8×½, HSS16×8×⅝, HSS20×12×⅝.
Common round HSS. HSS3.500×0.216, HSS4.500×0.237, HSS6.625×0.250, HSS6.625×0.500, HSS8.625×0.322, HSS10.750×0.250, HSS10.750×0.500, HSS14.000×0.500, HSS16.000×0.500.
Use cases. Exposed framing (architectural visual quality), bracing in lateral systems, columns where biaxial loading or torsion matters, truss members. Note: A500 design wall thickness is 0.93t for square/rectangular per AISC Manual Part 1; A1085 uses full t.
8. Pipe (AISC, ASME)
ASTM A53 Gr.B — welded or seamless, Fy = 240 MPa (35 ksi), Fu = 414 MPa (60 ksi). Most common structural pipe.
ASTM A106 Gr.B — seamless, higher temp/pressure use, sometimes used structurally.
Designation per ASME B36.10M (carbon steel) and B36.19M (stainless): nominal pipe size (NPS) + schedule (40 / 80 / 160) or strength category (Std / X-Strong / XX-Strong).
| NPS | DN | OD mm (in) | t Std mm (Sch 40) | t X-Strong (Sch 80) | t XX-Strong |
|---|---|---|---|---|---|
| 1 | 25 | 33.4 (1.315) | 3.38 (0.133) | 4.55 (0.179) | 9.09 (0.358) |
| 2 | 50 | 60.3 (2.375) | 3.91 (0.154) | 5.54 (0.218) | 11.07 (0.436) |
| 3 | 80 | 88.9 (3.500) | 5.49 (0.216) | 7.62 (0.300) | 15.24 (0.600) |
| 4 | 100 | 114.3 (4.500) | 6.02 (0.237) | 8.56 (0.337) | 17.12 (0.674) |
| 6 | 150 | 168.3 (6.625) | 7.11 (0.280) | 10.97 (0.432) | 21.95 (0.864) |
| 8 | 200 | 219.1 (8.625) | 8.18 (0.322) | 12.70 (0.500) | 22.23 (0.875) |
| 10 | 250 | 273.1 (10.75) | 9.27 (0.365) | 12.70 (0.500) | 25.40 (1.000) |
| 12 | 300 | 323.9 (12.75) | 9.53 (0.375) | 12.70 (0.500) | 25.40 (1.000) |
AISC Manual Part 1 Table 1-14 lists structural pipe properties for Std/X-Strong/XX-Strong sections; design wall thickness is 0.93t (per A53 manufacturing tolerances).
Use cases. Columns (Pipe 4-Std to Pipe 12-XX-Strong span typical column loads), handrails (Pipe 1¼-Std or Pipe 1½-Std), pipe rack supports, light bracing, architectural columns. Round HSS often preferred over A53 pipe in new design due to higher Fy and tighter tolerances.
9. European IPE / HE / UPN / UPE / L (EN)
Material. EN 10025-2 grades S235JR, S275JR, S355JR, S460M (Fy in MPa = numeric suffix). S355 is the European default; S460 used for heavy / weight-critical work.
9.1 IPE — parallel-flange I-beam
- Range IPE 80 to IPE 600 (some mills roll to IPE 750 OWB / Wide-flange Beam variants)
- Constant flange/web slenderness ratio across the series — designed for plastic moment efficiency
- Example: IPE 200 — d = 200 mm, bf = 100 mm, tf = 8.5 mm, tw = 5.6 mm, mass = 22.4 kg/m
- Example: IPE 400 — d = 400 mm, bf = 180 mm, tf = 13.5 mm, tw = 8.6 mm, mass = 66.3 kg/m
- Example: IPE 600 — d = 600 mm, bf = 220 mm, tf = 19.0 mm, tw = 12.0 mm, mass = 122 kg/m
- Typical use: floor and roof beams; the European equivalent of W16-W24 light beams
9.2 HE — wide-flange H-section (three weight classes)
- HEA (light): b ≈ d, thin flange/web — use where weight matters
- HEB (standard): b = d for sizes ≤ HE300 (truly square); heavier than HEA — the standard column choice
- HEM (heavy): thick flange/web — heavy columns, transfer girders, beam-to-column moment connections
- HEAA (extra-light, when offered): thinner than HEA, weight-critical
Range HE 100 to HE 1000. Selected sizes:
| Designation | d mm | b mm | tf mm | tw mm | Mass kg/m |
|---|---|---|---|---|---|
| HEA 200 | 190 | 200 | 10.0 | 6.5 | 42.3 |
| HEB 200 | 200 | 200 | 15.0 | 9.0 | 61.3 |
| HEM 200 | 220 | 206 | 25.0 | 15.0 | 103 |
| HEA 300 | 290 | 300 | 14.0 | 8.5 | 88.3 |
| HEB 300 | 300 | 300 | 19.0 | 11.0 | 117 |
| HEM 300 | 340 | 310 | 39.0 | 21.0 | 238 |
| HEA 500 | 490 | 300 | 23.0 | 12.0 | 155 |
| HEB 500 | 500 | 300 | 28.0 | 14.5 | 187 |
| HEM 500 | 524 | 306 | 40.0 | 21.0 | 270 |
9.3 UPN / UPE — channels
- UPN (older, sloped flange) — DIN 1026-1: UPN 50 to UPN 400. Example: UPN 200, d = 200 mm, b = 75 mm, mass = 25.3 kg/m. UPN tends to be deeper for a given mass than UPE.
- UPE (modern, parallel flange) — EN 10365: UPE 80 to UPE 400. Example: UPE 200, d = 200 mm, b = 80 mm, mass = 22.8 kg/m. Easier connection detailing (square flange).
9.4 L — angles
EN 10056-1 covers equal-leg and unequal-leg angles. Range L20×20×3 to L250×250×35 (equal); L 75×50×6 to L 250×90×16 (unequal). Materials: S235 / S275 / S355. Used for bracing, truss webs, cleats — same role as US L.
9.5 CHS / RHS / SHS — hollow sections
EN 10210 — hot-finished (S235J2H / S275J2H / S355J2H / S460NLH); structural designation when hot-formed quality with full corner radius is needed. EN 10219 — cold-formed welded (S235JRH / S275JRH / S355J2H); thinner walls available, sharper corners, more common for stock.
Round (CHS): 21.3×2.6 to 1219×40 (depends on mill). Square (SHS): 20×20×2 to 400×400×16. Rectangular (RHS): 40×20×2 to 500×300×16.
10. Sheet, plate, bar
10.1 Sheet — thin (US Manufacturer’s Standard Gauge for steel sheet)
| Gauge | t in | t mm |
|---|---|---|
| 7 | 0.179 | 4.55 |
| 10 | 0.135 | 3.42 |
| 12 | 0.105 | 2.66 |
| 14 | 0.0747 | 1.90 |
| 16 | 0.0598 | 1.52 |
| 18 | 0.0478 | 1.21 |
| 20 | 0.0359 | 0.911 |
| 24 | 0.0239 | 0.607 |
| 30 | 0.0120 | 0.305 |
(Approximate; ASTM A568M is the controlling spec. “16 ga” ≈ 0.060″ ≈ 1.5 mm is a common mental shorthand.) USS gauge differs from Manufacturer’s Standard slightly; designers should specify thickness in mm or inches, not gauge, on shop drawings.
10.2 Plate — t ≥ 3/16″ (≈ 5 mm) by AISC convention
Coil widths: 36, 48, 60, 72, 96 in (914, 1219, 1524, 1829, 2438 mm). Mill plate widths commonly to 120 in (3048 mm) or wider with special order.
Standard plate panel sizes (cut from coil or as discrete plate):
- 4×8 ft (1219×2438 mm)
- 4×10 ft (1219×3048 mm)
- 5×10 ft (1524×3048 mm)
- 5×20 ft (1524×6096 mm)
- 8×20 ft (2438×6096 mm)
- 8×40 ft (2438×12190 mm) — heavy-plate, e.g., girder web
Material: A36 (general), A572 Gr.50 (preferred for moment connections), A588 (weathering exposed steel), A516 Gr.70 (pressure vessel), A709 (bridge), A514 (high-strength quenched-tempered).
10.3 Bar — flat, square, round
- Flat bar (FB): t × b, e.g., FB ¼×3 (6.4×76 mm), FB ½×6 (12.7×152 mm) up to FB 1×12 (25×305 mm) and beyond as merchant bar
- Square bar: ½×½ to 4×4 in; merchant bar A36
- Round bar: ¼ in (6.4 mm) to 6 in (152 mm) commonly; ASTM A36 hot-rolled or A108 cold-drawn (CRS) for tighter tolerance / smoother finish
Hot-rolled (HRS) bar: rougher surface, mill scale, dimensional tolerance ±. Cold-rolled / cold-drawn (CRS): smoother, tighter tolerance, slightly higher yield, work-hardened surface — for shafts, pins, machined parts.
11. Material specifications
| Spec | Yield Fy MPa (ksi) | Tensile Fu MPa (ksi) | Use |
|---|---|---|---|
| ASTM A36 | 250 (36) | 400-550 (58-80) | General structural, plate, bar, M, S; historically W but supplanted by A992 |
| ASTM A992 | 345-450 (50-65) | 450 min (65) | The standard for W-shapes since 1998, also HP. CVN required. Tighter chemistry than A36. |
| ASTM A572 Gr.50 | 345 (50) | 450 (65) | Plate (gusset, connection), HP, MC, C in heavier grade. Often spec’d for plate to match A992 W |
| ASTM A588 | 345 (50) | 485 (70) | Weathering steel (Cor-Ten equivalent) — exposed bridges, architectural |
| ASTM A500 Gr.B / Gr.C | 290-345 (42-50) | 400-427 (58-62) | HSS — square, rect, round, cold-formed welded |
| ASTM A1085 | 345 (50) | 450 (65) | HSS, tighter wall tolerance + higher CVN. Preferred for new work where available. |
| ASTM A53 Gr.B | 240 (35) | 414 (60) | Pipe (welded or seamless), structural and pressure |
| ASTM A106 Gr.B | 240 (35) | 414 (60) | Seamless pipe, high-temp pressure piping, sometimes structural |
| ASTM A709 | 250-690 (36-100) | varies | Bridge-grade plate, replaces A36/A572/A588/A514 for FHWA work |
| EN 10025-2 S235JR | 235 | 360-510 | EU general structural (rolled) |
| EN 10025-2 S355JR / J2 | 355 | 470-630 | EU default for moment frames, hot-rolled |
| EN 10025-4 S460M | 460 | 540-720 | Heavy / weight-critical EU |
| EN 10210 / 10219 S355J2H | 355 | 470 | EU CHS / RHS / SHS hot-formed / cold-formed |
Notes on substitution.
- A992 replaced A36 as the default W-shape spec in 1998 (ASTM A6 reorganization). Most W rolled today is A992 by default; A36 W is special-order.
- A572 Gr.50 plate is the typical match for A992 W in moment connections.
- A36 still used routinely for angles, light channels, plate stiffeners, base plates.
- Imperial vs SI: a 345 MPa = 50 ksi yield is the same physical material — spec’d by ASTM in US, EN in Europe.
12. Selection heuristics
| Application | First-pick shape | Rationale |
|---|---|---|
| Office floor beam, 6-9 m span | W14 to W21 (W360 to W530) | High Sx/A, composite-deck-friendly |
| Long-span beam (10-15 m) | W24 to W36 (W610 to W920) | Deeper for serviceability and stiffness |
| Building column, 3-5 storey | W10 / W12 (W250 / W310) | Square-ish, biaxial-balanced |
| Building column, 6-12 storey | W14 (W360) | Standard column depth, accommodates heavier loads |
| Tall column (15+ storey) | W14×heavy or built-up plate | W14×120 to W14×730 |
| Concentric brace (CBF) | HSS square (A500 / A1085) or 2L back-to-back | Equal-axis stiffness, slenderness-friendly |
| Eccentric brace (EBF link) | W-shape (compact, web-yielding) | Predictable ductile mechanism |
| Truss chord, top | WT or 2L star | Flange-up for purlin contact; web continuity |
| Truss web | 2L back-to-back or single L | Cleat-friendly, slender |
| Gusset plate | A572 Gr.50 plate | Match Fy with A992 W-flange |
| Stiffener / bearing plate | A36 plate or A572 Gr.50 | Per AISC 360 Chapter J |
| Foundation pile | HP (HP10 to HP14) | Equal-thickness flange/web; survives driving |
| Mat foundation reinforcement frame | A572 plate built-up | Heavy plate for embed |
| Perimeter spandrel beam | HSS rectangular | Closed section, torsional stiffness for cantilever balcony / cladding |
| Architectural exposed column | HSS round (A500 / A1085) or Pipe | Clean profile, paint-friendly |
| Light frame purlin (joist roof) | Cold-formed Cee (CFS) or Zee | Light, screw-installable |
| Heavy roof purlin | C or MC | Channel section, sloped flange seats decking |
| Industrial portal frame | Built-up plate girder or HEB | Tapered web, custom geometry |
| Tower mast / lattice | CHS or HSS round | Symmetric in all directions for wind |
| Deck framing (joist) | Open-Web Steel Joist (OWSJ, SJI) | Light, factory-fabricated, standard depths K-series / LH-series |
| Heavy crane runway | W with cap channel or built-up | High Sx; cap C provides lateral capacity |
| Storage rack column | Cold-formed C / lipped C (proprietary) | Light, drilled for clip-in beams |
13. Cold-formed shapes (AISI / SSMA)
Standards. AISI S100 (North American Specification for the Design of Cold-Formed Steel Structural Members), with SSMA (Steel Stud Manufacturers Association) standard product table per “Product Technical Information” 2021.
Designations (SSMA). {depth}{shape}{flange-width}-{mil thickness} where depth and flange are in 1/100 in and thickness is mil (1 mil = 0.001 in). Shape letter: S (stud, C-shape with lips), T (track, plain C), U (unstiffened C), F (furring).
- 362S162-43 — 3⅝ in deep stud with 1⅝ in flange, 43 mil (0.0451 in / 1.15 mm) thickness. Common interior partition stud (16 ga equivalent).
- 600S162-54 — 6 in deep stud, 1⅝ in flange, 54 mil (≈ 16 ga in industry usage). Common exterior load-bearing stud.
- 800S200-68 — 8 in deep stud, 2 in flange, 68 mil. Heavy-load load-bearing stud / joist.
- 1200S200-97 — 12 in deep joist, 97 mil. Floor or roof joist for cold-formed framing.
- 362T125-33 — 3⅝ in track, 1¼ in flange, 33 mil. Track / runner for studs.
Shape families.
- C (Cee) with lips — the workhorse cold-formed stud / joist. Lips stiffen the flange.
- Z (Zee) — anti-symmetric; used as purlin in metal building systems
- Hat section — open-on-bottom, flanges out; bracing, furring
- Sigma (Σ) — stiffened C with intermediate bends; deeper / stiffer for given thickness; European preference
- Track / U — open C without lips, used as floor / head runner
Materials. ASTM A1003 (sheet steel for cold-forming), grades 33, 50, 65, 80 ksi (Fy in ksi). G60 / G90 galvanized coating typical for exterior / wet conditions.
Design considerations. Effective width method per AISI S100 §B (or Direct Strength Method §E). Local, distortional, and global buckling all controlling — much more so than for hot-rolled. Connections: self-drilling screws (#10, #12, ¼ in), not welds (heat distorts thin sheet). Power-actuated fasteners to concrete.
14. Cross-references
- steel-design — AISC 360-22 design provisions, LRFD/ASD, buckling, connections
- steel-connection-design — bolted (A325, A490, A307), welded (CJP, PJP, fillet), bearing, slip-critical, prying action
- steel-grades — ASTM A36, A572, A992, A588, A500, A1085, A53, A106; EN 10025 grades
- fasteners-taxonomy — bolts, threaded rods, anchors, structural fasteners
- structural-analysis — frame analysis, P-Δ, second-order effects
- structural-analysis — gravity, wind, seismic, snow load combinations
- structural-shapes — AISI S100, effective width, distortional buckling
- structural-analysis — AASHTO LRFD, bridge-specific shape selection
- steel-connection-design — shop drawings, cutting, welding, galvanizing, paint
- structural-dynamics — AISC 341 seismic provisions, SCBF, OCBF, SMF, IMF, OMF
15. Citations
- AISC Steel Construction Manual, 16th ed., American Institute of Steel Construction, Chicago, 2023. Part 1: Dimensions and Properties. Tables 1-1 through 1-15.
- AISC 360-22 Specification for Structural Steel Buildings, ANSI/AISC 360-22, 2022. Chapters B, D-K.
- AISC 341-22 Seismic Provisions for Structural Steel Buildings, ANSI/AISC 341-22, 2022.
- ASTM A6/A6M-22, Standard Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling. ASTM International, 2022.
- ASTM A36/A36M-19, Specification for Carbon Structural Steel.
- ASTM A992/A992M-22, Specification for Structural Steel Shapes (W-shape default).
- ASTM A572/A572M-21e1, Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel.
- ASTM A500/A500M-23, Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing.
- ASTM A1085/A1085M-15, Specification for Cold-Formed Welded Carbon Steel HSS.
- ASTM A53/A53M-22, Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless.
- ASTM A106/A106M-22b, Specification for Seamless Carbon Steel Pipe for High-Temperature Service.
- ASTM A588/A588M-19, Specification for High-Strength Low-Alloy Structural Steel (weathering).
- ASTM A709/A709M-22, Specification for Structural Steel for Bridges.
- EN 10025-2:2019 Hot rolled products of structural steels — Part 2: Technical delivery conditions for non-alloy structural steels (S235, S275, S355, S450).
- EN 10025-4:2019 — Part 4: Thermomechanical rolled weldable fine grain structural steels (S420M, S460M).
- EN 10210-1/2:2019 Hot finished structural hollow sections of non-alloy and fine grain steels.
- EN 10219-1/2:2019 Cold formed welded structural hollow sections of non-alloy and fine grain steels.
- EN 10365:2017 Hot rolled steel channels, I and H sections — Dimensions and masses.
- EN 10056-1:2017 Structural steel equal and unequal leg angles — Part 1: Dimensions.
- AISI S100-16 (R2020) North American Specification for the Design of Cold-Formed Steel Structural Members.
- SSMA Product Technical Information, Steel Stud Manufacturers Association, 2021.
- ASME B36.10M-2022, Welded and Seamless Wrought Steel Pipe.
- ASME B36.19M-2022, Stainless Steel Pipe.
- AISC Design Guide 24, Hollow Structural Section Connections, 2nd ed., 2018.
- Steel Tube Institute, https://www.steeltube.org/ — HSS member resources, A1085 advocacy, design aids.
- ArcelorMittal Sections Catalogue, “European profiles,” current edition — IPE / HE / UPE / UPN reference dimensions.