{ "version": "2026-10-20", "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.", "slug": "acme-threads-asme-b1-5-1-4-to-2-in", "name": "Acme threads 1/4-16 to 2-4 (ASME B1.5): 1/2-10, 5/8-8, 3/4-6, 1-5, 1-1/2-4, 2-4: major, pitch and minor diameter, pitch", "kind": "standard", "category": "Hardware", "group": "Bearings, rails & motion", "year": null, "question": "What are the major, pitch and minor diameters and the pitch of 1/2-10, 5/8-8, 3/4-6, 1-5 and 2-4 Acme lead screw threads?", "tags": [ "Acme thread", "ASME B1.5", "1/2-10 Acme", "5/8-8 Acme", "3/4-6 Acme", "1-5 Acme", "lead screw thread inch", "acme lead screw sizes", "tool" ], "aliases": [ "1/4-16 Acme dimensions", "5/16-14 Acme dimensions", "3/8-12 Acme dimensions", "1/2-10 Acme dimensions", "5/8-8 Acme dimensions", "3/4-6 Acme dimensions", "7/8-6 Acme dimensions", "1-5 Acme dimensions", "1-1/4-5 Acme dimensions", "1-1/2-4 Acme dimensions", "2-4 Acme dimensions", "Acme thread chart", "Acme thread pitch diameter", "Acme thread minor diameter", "ACME lead screw TPI", "1/2-10 acme pitch diameter", "3/4-6 acme minor diameter", "acme vs trapezoidal thread", "ASME B1.5 thread table", "acme thread 29 degree" ], "overall_mm": { "length": null, "width": null, "height": null }, "official_cad": false, "xem_status": "not-scanned", "les": false, "free_files": 0, "url": "https://xemstudio.com/objects/acme-threads-asme-b1-5-1-4-to-2-in/", "sheet_txt": "https://xemstudio.com/objects/acme-threads-asme-b1-5-1-4-to-2-in/sheet.txt", "sheet": { "basis": "Bornemann Gewindetechnik ASME B1.5 nominal-dimension table with formula checks on every row and MachiningDoctor pages for 5/16-14 and 2-4; numbers only", "overall_mm": { "length": null, "width": null, "height": null }, "notes": [ "General-purpose Acme (ASME B1.5, 29 degree flank angle) is the inch lead-screw thread: 1/2-10 Acme is a 1/2 in screw with 10 threads per inch, so the pitch (and, single-start, the lead) is 0.100 in. The basic formulas are d2 = d - P/2 and d1 = d - P; the generator checks both, and P = 1/TPI, on every row.", "Numbers: Bornemann Gewindetechnik's ASME B1.5 nominal-dimension table (inches as printed), with MachiningDoctor's 5/16-14 and 2-4 pages as the independent check (5/16-14: major 0.3125, pitch 0.2768, minor 0.2411, pitch 0.07143; 2-4: pitch diameter 1.875, minor 1.75, pitch 0.25). The mm columns are the printed inch values times 25.4 (rounded to 0.01 mm). Bornemann's table runs on to 5-2 Acme; only 1/4 to 2 in are shown here.", "Numbers only, no files: lead, start count and length are the user's choices and the helical form is not a published envelope. The Class 2G / 3G / 4G tolerance bands (MachiningDoctor prints them, e.g. 2-4 external pitch diameter 1.8402 to 1.8637 in) are left out.", "Left out: stub Acme, centralizing Acme, Class 2G / 3G / 4G limits, multi-start leads, sizes above 2 in, the metric Tr thread (separate page)." ], "table": { "columns": [ "thread", "TPI", "major Ø d, in", "pitch P, in", "pitch Ø d2, in", "minor Ø d1, in", "d, mm", "P, mm", "d2, mm", "d1, mm" ], "rows": [ [ "1/4-16 Acme", "16", "0.2500", "0.0625", "0.2188", "0.1875", "6.35", "1.59", "5.56", "4.76" ], [ "5/16-14 Acme", "14", "0.3125", "0.0714", "0.2768", "0.2411", "7.94", "1.81", "7.03", "6.12" ], [ "3/8-12 Acme", "12", "0.3750", "0.0833", "0.3333", "0.2917", "9.53", "2.12", "8.47", "7.41" ], [ "7/16-12 Acme", "12", "0.4375", "0.0833", "0.3958", "0.3542", "11.11", "2.12", "10.05", "9.00" ], [ "1/2-10 Acme", "10", "0.5000", "0.1000", "0.4500", "0.4000", "12.70", "2.54", "11.43", "10.16" ], [ "5/8-8 Acme", "8", "0.6250", "0.1250", "0.5625", "0.5000", "15.88", "3.18", "14.29", "12.70" ], [ "3/4-6 Acme", "6", "0.7500", "0.1667", "0.6667", "0.5833", "19.05", "4.23", "16.93", "14.82" ], [ "7/8-6 Acme", "6", "0.8750", "0.1667", "0.7917", "0.7083", "22.23", "4.23", "20.11", "17.99" ], [ "1-5 Acme", "5", "1.0000", "0.2000", "0.9000", "0.8000", "25.40", "5.08", "22.86", "20.32" ], [ "1-1/8-5 Acme", "5", "1.1250", "0.2000", "1.0250", "0.9250", "28.58", "5.08", "26.04", "23.50" ], [ "1-1/4-5 Acme", "5", "1.2500", "0.2000", "1.1500", "1.0500", "31.75", "5.08", "29.21", "26.67" ], [ "1-3/8-4 Acme", "4", "1.3750", "0.2500", "1.2500", "1.1250", "34.93", "6.35", "31.75", "28.58" ], [ "1-1/2-4 Acme", "4", "1.5000", "0.2500", "1.3750", "1.2500", "38.10", "6.35", "34.93", "31.75" ], [ "1-3/4-4 Acme", "4", "1.7500", "0.2500", "1.6250", "1.5000", "44.45", "6.35", "41.28", "38.10" ], [ "2-4 Acme", "4", "2.0000", "0.2500", "1.8750", "1.7500", "50.80", "6.35", "47.63", "44.45" ] ] } }, "sheet_text": "Acme threads 1/4-16 to 2-4 (ASME B1.5): 1/2-10, 5/8-8, 3/4-6, 1-5, 1-1/2-4, 2-4: major, pitch and minor diameter, pitch — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/acme-threads-asme-b1-5-1-4-to-2-in/ (sheet CC BY 4.0)\nBasis: Bornemann Gewindetechnik ASME B1.5 nominal-dimension table with formula checks on every row and MachiningDoctor pages for 5/16-14 and 2-4; numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- General-purpose Acme (ASME B1.5, 29 degree flank angle) is the inch lead-screw thread: 1/2-10 Acme is a 1/2 in screw with 10 threads per inch, so the pitch (and, single-start, the lead) is 0.100 in. The basic formulas are d2 = d - P/2 and d1 = d - P; the generator checks both, and P = 1/TPI, on every row.\n- Numbers: Bornemann Gewindetechnik's ASME B1.5 nominal-dimension table (inches as printed), with MachiningDoctor's 5/16-14 and 2-4 pages as the independent check (5/16-14: major 0.3125, pitch 0.2768, minor 0.2411, pitch 0.07143; 2-4: pitch diameter 1.875, minor 1.75, pitch 0.25). The mm columns are the printed inch values times 25.4 (rounded to 0.01 mm). Bornemann's table runs on to 5-2 Acme; only 1/4 to 2 in are shown here.\n- Numbers only, no files: lead, start count and length are the user's choices and the helical form is not a published envelope. The Class 2G / 3G / 4G tolerance bands (MachiningDoctor prints them, e.g. 2-4 external pitch diameter 1.8402 to 1.8637 in) are left out.\n- Left out: stub Acme, centralizing Acme, Class 2G / 3G / 4G limits, multi-start leads, sizes above 2 in, the metric Tr thread (separate page).\n\nthread TPI major Ø d, in pitch P, in pitch Ø d2, in minor Ø d1, in d, mm P, mm d2, mm d1, mm\n1/4-16 Acme 16 0.2500 0.0625 0.2188 0.1875 6.35 1.59 5.56 4.76\n5/16-14 Acme 14 0.3125 0.0714 0.2768 0.2411 7.94 1.81 7.03 6.12\n3/8-12 Acme 12 0.3750 0.0833 0.3333 0.2917 9.53 2.12 8.47 7.41\n7/16-12 Acme 12 0.4375 0.0833 0.3958 0.3542 11.11 2.12 10.05 9.00\n1/2-10 Acme 10 0.5000 0.1000 0.4500 0.4000 12.70 2.54 11.43 10.16\n5/8-8 Acme 8 0.6250 0.1250 0.5625 0.5000 15.88 3.18 14.29 12.70\n3/4-6 Acme 6 0.7500 0.1667 0.6667 0.5833 19.05 4.23 16.93 14.82\n7/8-6 Acme 6 0.8750 0.1667 0.7917 0.7083 22.23 4.23 20.11 17.99\n1-5 Acme 5 1.0000 0.2000 0.9000 0.8000 25.40 5.08 22.86 20.32\n1-1/8-5 Acme 5 1.1250 0.2000 1.0250 0.9250 28.58 5.08 26.04 23.50\n1-1/4-5 Acme 5 1.2500 0.2000 1.1500 1.0500 31.75 5.08 29.21 26.67\n1-3/8-4 Acme 4 1.3750 0.2500 1.2500 1.1250 34.93 6.35 31.75 28.58\n1-1/2-4 Acme 4 1.5000 0.2500 1.3750 1.2500 38.10 6.35 34.93 31.75\n1-3/4-4 Acme 4 1.7500 0.2500 1.6250 1.5000 44.45 6.35 41.28 38.10\n2-4 Acme 4 2.0000 0.2500 1.8750 1.7500 50.80 6.35 47.63 44.45\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Bornemann Gewindetechnik: ACME thread according to ANSI / ASME B1.5-1977, nominal dimensions: d, d2 = D2, P, d1, 1/4-16 to 5-2 (with 3D model links) — web — Publisher's page; dimensions are facts — https://www.bornemann-gewindetechnik.de/en/products/acme-screws-and-leadscrews/data/\n- MachiningDoctor: Acme thread basic dimensions (ASME B1.5): 5/16-14 and 2-4 pages (TPI, pitch, major, pitch, minor diameter) — web — Publisher's page; dimensions are facts — https://www.machiningdoctor.com/threadinfo-acme/?tid=5001\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=acme-threads-asme-b1-5-1-4-to-2-in\n", "sources": [ { "publisher": "Bornemann Gewindetechnik", "title": "ACME thread according to ANSI / ASME B1.5-1977, nominal dimensions: d, d2 = D2, P, d1, 1/4-16 to 5-2 (with 3D model links)", "url": "https://www.bornemann-gewindetechnik.de/en/products/acme-screws-and-leadscrews/data/", "formats": [ "web" ], "license": "Publisher's page; dimensions are facts", "license_verified": true, "hosted": false }, { "publisher": "MachiningDoctor", "title": "Acme thread basic dimensions (ASME B1.5): 5/16-14 and 2-4 pages (TPI, pitch, major, pitch, minor diameter)", "url": "https://www.machiningdoctor.com/threadinfo-acme/?tid=5001", "formats": [ "web" ], "license": "Publisher's page; dimensions are facts", "license_verified": true, "hosted": false } ], "xem": { "status": "not-scanned", "sheet_free": true, "mesh_price_usd": null, "step_price_usd": null, "tolerance_mm": null }, "related": [ "trapezoidal-threads-tr10-tr40-iso-2904", "t8-lead-screw", "lead-screw-tr10x2-l80-journals-6", "lead-screw-and-slide-mechanism", "thrust-ball-bearings-51100-series" ], "fits": [], "dimensions": "exact (nominal, no tolerance added)", "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no tolerance added. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn. Typical accuracy by process and ISO 286 fits: https://xemstudio.com/tolerances/", "mating": [], "faq": [ { "q": "What are the dimensions of a 1/2-10 Acme thread?", "a": "Major diameter 0.5000 in (12.70 mm), 10 TPI (pitch 0.1000 in = 2.54 mm), pitch diameter 0.4500 in, minor diameter 0.4000 in (Bornemann, ASME B1.5)." }, { "q": "What are the dimensions of a 3/4-6 Acme thread?", "a": "Major 0.7500 in, 6 TPI (pitch 0.1667 in), pitch diameter 0.6667 in, minor diameter 0.5833 in." }, { "q": "What are the dimensions of a 1-5 Acme thread?", "a": "Major 1.0000 in, 5 TPI (pitch 0.2000 in), pitch diameter 0.9000 in, minor 0.8000 in." }, { "q": "What are the dimensions of a 2-4 Acme thread?", "a": "Major 2.0000 in, 4 TPI (pitch 0.2500 in), pitch diameter 1.8750 in, minor 1.7500 in; MachiningDoctor gives the same." }, { "q": "How do I get the pitch diameter of an Acme thread?", "a": "d2 = d - P/2 and the minor diameter d1 = d - P, with P = 1/TPI." } ], "files_license": null, "offers": [], "markdown": "https://xemstudio.com/objects/acme-threads-asme-b1-5-1-4-to-2-in/index.md" }