Square and rectangular steel tube sizes by gauge (1x1, 1-1/2, 2x1 in; 16, 14, 11 ga) + ASTM A500 corner radius limit, weight per foot — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/steel-square-rectangular-tube-gauge-sizes/ (sheet CC BY 4.0) Basis: Sugar Steel square tubing chart and Continental Steel rectangular tube listings for size, wall and lb/ft; corner-radius limit from the ASTM A500 text as quoted by Industrial Tube and Chicago Tube; numbers only, no file Catalog version: 2026-10-20 Sizes: see table below - Square and rectangular steel tube under about 2 in is mostly sold by gauge and made as mechanical tube: Industrial Tube Corp. says outside dimensions under 2 in with a wall under 0.120 in are typically ASTM A513, and 2 in and larger with 0.120 in and heavier are typically ASTM A500. So '1x1 A500' and '1-1/2 sq A500' are usually A513 in practice; the geometry and the 3t corner limit below are the same ideas either way. - ASTM A500 corner radius: 'the radius of any outside corner of the section shall not exceed three times the specified wall thickness' (A500 section 10.6, quoted by Industrial Tube, Chicago Tube, Speedy Metals; the Steel Tube Institute article says the same, 3 x t). The wall-thickness tolerance does not apply at corners. There is no nominal radius in A500, so no file is drawn here. - A500 tolerances (Industrial Tube Corp.): outside dimension +/-0.020 in for the largest side 1 to 2-1/2 in, +/-0.025 in over 2-1/2 to 3-1/2 in, +/-0.030 in over 3-1/2 to 5-1/2 in, +/-1 % above that; wall +/-10 %. - Sizes at 2 in and up in the AISC HSS database (HSS2x2x1/8 and heavier, with the true AISC walls) are on aisc-hss-rectangular-square with files; this page lists only what that page does not: sizes under 2 in and gauge walls (16, 14, 11 ga) in squares, plus the rectangular gauge sizes from Continental Steel. Weights are as printed by the distributors; they are nominal and different sources allow for the corner radius differently (gauge walls match a sharp-corner estimate to about 1 %; the heavier walls print up to 13% less, which is the corner allowance). - Gauge walls match what McMaster-Carr lists: its square and rectangular tube pages show wall thicknesses 0.035, 0.049, 1/16, 0.065, 0.083, 0.120, 1/8, 0.188, 1/4, 5/16, 3/8 and 1/2 in, and outside sizes from 3/8 to 8 in. McMaster has the per-part STEP; Xem links it and does not copy it. - Rectangular sizes 2x3, 2x4, 3x4 and so on are on the AISC page. Cold-formed C and Z purlins are not listed: no public standard table exists (each metal-building maker has its own sizes). size (in) wall name as printed wall (in) wall (mm) outside H (mm) outside B (mm) weight (lb/ft) weight (kg/m) A500 max outside corner radius 3t (mm) 1/2 sq 18 ga 0.049 1.24 12.7 12.7 0.3005 0.447 3.73 1/2 sq 16 ga 0.065 1.65 12.7 12.7 0.3845 0.572 4.95 3/4 sq 18 ga 0.049 1.24 19.0 19.0 0.4671 0.695 3.73 3/4 sq 16 ga 0.065 1.65 19.0 19.0 0.6055 0.901 4.95 3/4 sq 14 ga 0.083 2.11 19.0 19.0 0.7528 1.12 6.32 3/4 sq 11 ga 0.12 3.05 19.0 19.0 1.028 1.53 9.14 1 sq 16 ga 0.065 1.65 25.4 25.4 0.826 1.229 4.95 1 sq 14 ga 0.083 2.11 25.4 25.4 1.035 1.54 6.32 1 sq 11 ga 0.12 3.05 25.4 25.4 1.44 2.143 9.14 1-1/4 sq 16 ga 0.065 1.65 31.8 31.8 1.048 1.56 4.95 1-1/4 sq 14 ga 0.083 2.11 31.8 31.8 1.317 1.96 6.32 1-1/4 sq 11 ga 0.12 3.05 31.8 31.8 1.844 2.744 9.14 1-1/4 sq 3/16 0.188 4.78 31.8 31.8 2.4 3.572 14.33 1-1/2 sq 16 ga 0.065 1.65 38.1 38.1 1.269 1.888 4.95 1-1/2 sq 14 ga 0.083 2.11 38.1 38.1 1.6 2.381 6.32 1-1/2 sq 11 ga 0.12 3.05 38.1 38.1 2.252 3.351 9.14 1-1/2 sq 3/16 0.188 4.78 38.1 38.1 3.04 4.524 14.33 1-1/2 sq 1/4 0.25 6.35 38.1 38.1 3.7 5.506 19.05 1-3/4 sq 16 ga 0.065 1.65 44.4 44.4 1.49 2.217 4.95 1-3/4 sq 14 ga 0.083 2.11 44.4 44.4 1.882 2.801 6.32 1-3/4 sq 11 ga 0.12 3.05 44.4 44.4 2.66 3.959 9.14 1-3/4 sq 3/16 0.188 4.78 44.4 44.4 3.994 5.944 14.33 2 sq 16 ga 0.065 1.65 50.8 50.8 1.711 2.546 4.95 2 sq 14 ga 0.083 2.11 50.8 50.8 2.164 3.22 6.32 2 sq 11 ga 0.12 3.05 50.8 50.8 3.07 4.569 9.14 2-1/4 sq 14 ga 0.083 2.11 57.1 57.1 2.446 3.64 6.32 2-1/4 sq 11 ga 0.12 3.05 57.1 57.1 3.48 5.179 9.14 2-1/2 sq 14 ga 0.083 2.11 63.5 63.5 2.728 4.06 6.32 2-1/2 sq 11 ga 0.12 3.05 63.5 63.5 3.9 5.804 9.14 3 sq 14 ga 0.083 2.11 76.2 76.2 3.293 4.901 6.32 3 sq 11 ga 0.12 3.05 76.2 76.2 4.75 7.069 9.14 3-1/2 sq 11 ga 0.12 3.05 88.9 88.9 5.61 8.349 9.14 4 sq 11 ga 0.12 3.05 101.6 101.6 6.46 9.614 9.14 1-1/2 x 1 14 gauge 0.083 2.11 38.1 25.4 1.288 1.917 6.32 1-1/2 x 1 11 gauge 0.12 3.05 38.1 25.4 1.766 2.628 9.14 2 x 1 14 gauge 0.083 2.11 50.8 25.4 1.59 2.366 6.32 2 x 1-1/4 14 gauge 0.083 2.11 50.8 31.8 1.711 2.546 6.32 2 x 1-1/2 11 gauge 0.12 3.05 50.8 38.1 2.582 3.842 9.14 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Sugar Steel: Square tubing chart: nominal size, weight per foot, wall thickness (1/2 x 1/2 to 16 x 16) — web — Publisher's page; dimensions are facts — https://sugarsteel.com/wp-content/uploads/SquareTubingFull.pdf - Continental Steel & Tube: Rectangular structural tubing, carbon steel: 1-1/2 x 1 to 2 x 1-1/2, 14 and 11 gauge, lb/ft — web — Publisher's page; dimensions are facts — https://continentalsteel.com/compare/pipe-and-tubing/rectangular-structural-tubing-carbon-steel - Industrial Tube Corporation: ASTM A500 square and rectangular tube: outside corner radius not over 3 x wall; outside-dimension and wall tolerances — web — Publisher's page; dimensions are facts — https://www.industrialtube.com/tolerances/ - Industrial Tube Corporation: Rectangular structural tubing: under 2 in OD with wall under 0.120 in is typically ASTM A513; 2 in and up with 0.120 in and heavier is typically ASTM A500 — web — Publisher's page; dimensions are facts — https://www.industrialtube.com/rectangular-structural-tubing/ - Chicago Tube & Iron: ASTM A500 section 10.6: outside corner radius not over three times the specified wall; wall tolerance does not apply at corners — web — Publisher's page; dimensions are facts — https://www.chicagotube.com/products-2/square-rectangular-round-tubing/astm-a-500 - Steel Tube Institute: HSS article: the maximum corner radius for rectangular and square shapes is 3t; 10 % thickness tolerance — web — Publisher's page; dimensions are facts — https://steeltubeinstitute.org/wp-content/uploads/2022/08/HSS_Article_ASTM-080722.pdf - McMaster-Carr: Square hollow sections / square and rectangular tube, steel (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/square-hollow-sections - McMaster-Carr: Low-carbon steel rectangular tubes (ASTM A513 / A500; metric EN 10305-5) (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/low-carbon-steel-rectangular-tubes No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned. API: https://xemstudio.com/api/geometry?object=steel-square-rectangular-tube-gauge-sizes