S shapes (AISC American Standard beams): S6x12.5, S12x31.8 dimensions + STEP/STL — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/aisc-s-shapes/ (sheet CC BY 4.0) Basis: AISC Shapes Database (v15.0 values): d, bf, tw, tf, k for every S shape; 2:12 inner flange slope Catalog version: 2026-10-20 Overall (mm): length 101.6 - S shapes are the American Standard beams: narrower flanges than a W of the same depth, and flanges whose inner faces slope about 17 % (2 in 12 in). S12x31.8 means about 12 in deep and 31.8 lb per foot. - The tabulated flange thickness tf of a tapered flange is the mean thickness. The files draw the 2:12 slope (the figure is quoted on draftsperson.net, no AISC page was readable here) with tf at the middle of the flange projection, so the tip is thinner and the root thicker than tf. - Root radius is derived from the printed k (outside face of the flange to the web toe of the fillet) with the sloped flange: r = (k - root thickness) x tan((90 + slope angle)/2). Tips are square (no toe radius is printed). - Files are 4 in (101.6 mm) long extrusions along X; the section is in the YZ plane, centred on y = 0, with z = 0 on the bottom face. - 15 of the 28 S sizes have files; all are in the table. Drawn area is within 3 % of the printed area on all of them. shape lb/ft d (in) bf (in) tw (in) tf mean (in) k (in) d (mm) bf (mm) tw (mm) tf (mm) S24x121 121.0 24.5 8.05 0.8 1.09 2.0 622.3 204.5 20.32 27.69 S24x106 106.0 24.5 7.87 0.62 1.09 2.0 622.3 199.9 15.75 27.69 S24x100 100.0 24.0 7.25 0.745 0.87 1.75 609.6 184.1 18.92 22.1 S24x90 90.0 24.0 7.13 0.625 0.87 1.75 609.6 181.1 15.88 22.1 S24x80 80.0 24.0 7.0 0.5 0.87 1.75 609.6 177.8 12.7 22.1 S20x96 96.0 20.3 7.2 0.8 0.92 1.75 515.6 182.9 20.32 23.37 S20x86 86.0 20.3 7.06 0.66 0.92 1.75 515.6 179.3 16.76 23.37 S20x75 75.0 20.0 6.39 0.635 0.795 1.63 508.0 162.3 16.13 20.19 S20x66 66.0 20.0 6.26 0.505 0.795 1.63 508.0 159.0 12.83 20.19 S18x70 70.0 18.0 6.25 0.711 0.691 1.5 457.2 158.8 18.06 17.55 S18x54.7 54.7 18.0 6.0 0.461 0.691 1.5 457.2 152.4 11.71 17.55 S15x50 50.0 15.0 5.64 0.55 0.622 1.38 381.0 143.3 13.97 15.8 S15x42.9 42.9 15.0 5.5 0.411 0.622 1.38 381.0 139.7 10.44 15.8 S12x50 50.0 12.0 5.48 0.687 0.659 1.44 304.8 139.2 17.45 16.74 S12x40.8 40.8 12.0 5.25 0.462 0.659 1.44 304.8 133.3 11.73 16.74 S12x35 35.0 12.0 5.08 0.428 0.544 1.19 304.8 129.0 10.87 13.82 S12x31.8 31.8 12.0 5.0 0.35 0.544 1.19 304.8 127.0 8.89 13.82 S10x35 35.0 10.0 4.94 0.594 0.491 1.13 254.0 125.5 15.09 12.47 S10x25.4 25.4 10.0 4.66 0.311 0.491 1.13 254.0 118.4 7.9 12.47 S8x23 23.0 8.0 4.17 0.441 0.425 1.0 203.2 105.9 11.2 10.79 S8x18.4 18.4 8.0 4.0 0.271 0.425 1.0 203.2 101.6 6.88 10.79 S6x17.25 17.25 6.0 3.57 0.465 0.359 0.813 152.4 90.7 11.81 9.12 S6x12.5 12.5 6.0 3.33 0.232 0.359 0.813 152.4 84.6 5.89 9.12 S5x10 10.0 5.0 3.0 0.214 0.326 0.75 127.0 76.2 5.44 8.28 S4x9.5 9.5 4.0 2.8 0.326 0.293 0.75 101.6 71.1 8.28 7.44 S4x7.7 7.7 4.0 2.66 0.193 0.293 0.75 101.6 67.6 4.9 7.44 S3x7.5 7.5 3.0 2.51 0.349 0.26 0.625 76.2 63.8 8.86 6.6 S3x5.7 5.7 3.0 2.33 0.17 0.26 0.625 76.2 59.2 4.32 6.6 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - AISC (values via the ambaker1/aisc-csv extract, MIT): AISC Shapes Database v15.0 (W, S, C, MC, L, HSS): d, bf, tw, tf, k, t, HSS Ht, B, OD, tnom, tdes, A, weight — web — AISC publishes the database free of charge; dimensions are facts. aisc.org itself was not reachable from the build box — https://github.com/ambaker1/aisc-csv - AISC: Shapes Database (free download, v16.0 on aisc.org) - the values here are the v15.0 release; check the current release before relying on a size — web — Publisher's page; dimensions are facts — https://www.aisc.org/publications/steel-construction-manual-resources/ - draftsperson.net: Steel shapes and sizes: American Standard beams (S) and channels (C) have a slope of approximately 17 percent (2 in 12 in) on the inner flange surfaces — web — Publisher's page; dimensions are facts — https://blog.draftsperson.net/steel-shapes-and-sizes/ Free files (CC BY 4.0, Xem Studio; STEP + STL, 15 parts): https://xemstudio.com/files/hardware/aisc-s-shapes/index.json API: https://xemstudio.com/api/geometry?object=aisc-s-shapes