{
 "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": "trapezoidal-threads-tr10-tr40-iso-2904",
 "name": "Trapezoidal lead screw threads Tr10 to Tr40 (ISO 2904 / DIN 103): Tr10x2, Tr12x3, Tr16x4, Tr20x4, Tr24x5, Tr30x6, Tr40x7: pitch, d2, D4, d3, D1",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the pitch diameter, minor diameter and nut major diameter of a Tr10x2, Tr12x3, Tr16x4, Tr20x4, Tr24x5, Tr30x6 or Tr40x7 trapezoidal thread?",
 "tags": [
  "trapezoidal thread",
  "Tr10x2",
  "Tr12x3",
  "Tr16x4",
  "Tr20x4",
  "Tr24x5",
  "Tr30x6",
  "Tr40x7",
  "lead screw thread",
  "ISO 2904",
  "DIN 103",
  "acme alternative"
 ],
 "aliases": [
  "Tr10x2 thread dimensions",
  "Tr12x3 thread dimensions",
  "Tr14x3 thread dimensions",
  "Tr16x4 thread dimensions",
  "Tr20x4 thread dimensions",
  "Tr24x5 thread dimensions",
  "Tr30x6 thread dimensions",
  "Tr40x7 thread dimensions",
  "Tr8x2 dimensions",
  "Tr10x2 pitch diameter",
  "Tr10x2 minor diameter",
  "Tr12x3 minor diameter",
  "Tr16x4 d3",
  "Tr20x4 d2",
  "Tr10x2 lead screw",
  "Tr10x1.5 thread",
  "trapezoidal thread chart",
  "metric acme thread",
  "DIN 103 thread table",
  "ISO 2904 thread dimensions",
  "Tr thread pitch diameter formula",
  "trapezoidal lead screw sizes",
  "Tr16x4 core diameter",
  "Tr12x3 core diameter"
 ],
 "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/trapezoidal-threads-tr10-tr40-iso-2904/",
 "sheet_txt": "https://xemstudio.com/objects/trapezoidal-threads-tr10-tr40-iso-2904/sheet.txt",
 "sheet": {
  "basis": "ISO 2904:2020 sample table (iTeh) with formula checks on every row; fasten.it, Roymech and AmesWeb as comparison; numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Tr is the metric trapezoidal (30 degree flank angle) lead-screw thread: Tr10x2 means 10 mm nominal diameter and 2 mm pitch. For a single-start screw the lead equals the pitch; a multi-start thread has lead = P x starts and is written Tr d x lead (P pitch). The standard's formulas: D1 = d - P, d2 = D2 = d - 0.5 P, D4 = d + 2 ac, d3 = d - P - 2 ac (ac is the crest clearance, which differs by pitch).",
   "Numbers: the ISO 2904:2020 sample (iTeh) table for Tr10 to Tr40 (44 d x P combinations); the generator re-checks D1 = d - P, d2 = d - 0.5 P and d3 = d - P - 2 ac on every row (ac = (D4 - d) / 2). AmesWeb's limits tables print the same screw minor and nut major values where compared (Tr10x1.5: d3 8.200, D4 10.300; Tr16x4: d3 11.500; Tr40x7: d3 32.000).",
   "Disagreements kept: fasten.it's copy of the table (a cancelled-DIN reproduction) prints Tr10x1.5 with D4 11, d3 8 and D1 7.5, Roymech with D4 11, d3 2.000 and D1 3.000; the ISO 2904 sample and AmesWeb both give D4 10.3, d3 8.2, D1 8.5, which the formulas confirm. fasten.it, Roymech and AmesWeb also list Tr16x3 (and Tr18x3, Tr20x3 on AmesWeb), which the ISO 2904 sample table does not; Tr16x4 is in the ISO sample (and AmesWeb) but fasten.it and Roymech print Tr16x3 in its place. Those rows are not used here.",
   "Numbers only, no files: a lead screw's length, ends and start count are chosen by the user, and the helical thread is not a published envelope. For modelled lead screws see the T8 lead screw and the Tr10x2 screw pages.",
   "Left out: the external / internal tolerance classes (7e, 7H and so on), the multi-start leads, Tr sizes above 40 mm, ac / H4 / h3 values per pitch (not in the sample)."
  ],
  "table": {
   "columns": [
    "thread",
    "nominal Ø d, mm",
    "pitch P, mm",
    "pitch Ø d2 = D2, mm",
    "nut major Ø D4, mm",
    "screw minor Ø d3, mm",
    "nut minor Ø D1, mm"
   ],
   "rows": [
    [
     "Tr10x1.5",
     "10",
     "1.5",
     "9.250",
     "10.300",
     "8.200",
     "8.500"
    ],
    [
     "Tr10x2",
     "10",
     "2",
     "9.000",
     "10.500",
     "7.500",
     "8.000"
    ],
    [
     "Tr11x2",
     "11",
     "2",
     "10.000",
     "11.500",
     "8.500",
     "9.000"
    ],
    [
     "Tr11x3",
     "11",
     "3",
     "9.500",
     "11.500",
     "7.500",
     "8.000"
    ],
    [
     "Tr12x2",
     "12",
     "2",
     "11.000",
     "12.500",
     "9.500",
     "10.000"
    ],
    [
     "Tr12x3",
     "12",
     "3",
     "10.500",
     "12.500",
     "8.500",
     "9.000"
    ],
    [
     "Tr14x2",
     "14",
     "2",
     "13.000",
     "14.500",
     "11.500",
     "12.000"
    ],
    [
     "Tr14x3",
     "14",
     "3",
     "12.500",
     "14.500",
     "10.500",
     "11.000"
    ],
    [
     "Tr16x2",
     "16",
     "2",
     "15.000",
     "16.500",
     "13.500",
     "14.000"
    ],
    [
     "Tr16x4",
     "16",
     "4",
     "14.000",
     "16.500",
     "11.500",
     "12.000"
    ],
    [
     "Tr18x2",
     "18",
     "2",
     "17.000",
     "18.500",
     "15.500",
     "16.000"
    ],
    [
     "Tr18x4",
     "18",
     "4",
     "16.000",
     "18.500",
     "13.500",
     "14.000"
    ],
    [
     "Tr20x2",
     "20",
     "2",
     "19.000",
     "20.500",
     "17.500",
     "18.000"
    ],
    [
     "Tr20x4",
     "20",
     "4",
     "18.000",
     "20.500",
     "15.500",
     "16.000"
    ],
    [
     "Tr22x3",
     "22",
     "3",
     "20.500",
     "22.500",
     "18.500",
     "19.000"
    ],
    [
     "Tr22x5",
     "22",
     "5",
     "19.500",
     "22.500",
     "16.500",
     "17.000"
    ],
    [
     "Tr22x8",
     "22",
     "8",
     "18.000",
     "23.000",
     "13.000",
     "14.000"
    ],
    [
     "Tr24x3",
     "24",
     "3",
     "22.500",
     "24.500",
     "20.500",
     "21.000"
    ],
    [
     "Tr24x5",
     "24",
     "5",
     "21.500",
     "24.500",
     "18.500",
     "19.000"
    ],
    [
     "Tr24x8",
     "24",
     "8",
     "20.000",
     "25.000",
     "15.000",
     "16.000"
    ],
    [
     "Tr26x3",
     "26",
     "3",
     "24.500",
     "26.500",
     "22.500",
     "23.000"
    ],
    [
     "Tr26x5",
     "26",
     "5",
     "23.500",
     "26.500",
     "20.500",
     "21.000"
    ],
    [
     "Tr26x8",
     "26",
     "8",
     "22.000",
     "27.000",
     "17.000",
     "18.000"
    ],
    [
     "Tr28x3",
     "28",
     "3",
     "26.500",
     "28.500",
     "24.500",
     "25.000"
    ],
    [
     "Tr28x5",
     "28",
     "5",
     "25.500",
     "28.500",
     "22.500",
     "23.000"
    ],
    [
     "Tr28x8",
     "28",
     "8",
     "24.000",
     "29.000",
     "19.000",
     "20.000"
    ],
    [
     "Tr30x3",
     "30",
     "3",
     "28.500",
     "30.500",
     "26.500",
     "27.000"
    ],
    [
     "Tr30x6",
     "30",
     "6",
     "27.000",
     "31.000",
     "23.000",
     "24.000"
    ],
    [
     "Tr30x10",
     "30",
     "10",
     "25.000",
     "31.000",
     "19.000",
     "20.000"
    ],
    [
     "Tr32x3",
     "32",
     "3",
     "30.500",
     "32.500",
     "28.500",
     "29.000"
    ],
    [
     "Tr32x6",
     "32",
     "6",
     "29.000",
     "33.000",
     "25.000",
     "26.000"
    ],
    [
     "Tr32x10",
     "32",
     "10",
     "27.000",
     "33.000",
     "21.000",
     "22.000"
    ],
    [
     "Tr34x3",
     "34",
     "3",
     "32.500",
     "34.500",
     "30.500",
     "31.000"
    ],
    [
     "Tr34x6",
     "34",
     "6",
     "31.000",
     "35.000",
     "27.000",
     "28.000"
    ],
    [
     "Tr34x10",
     "34",
     "10",
     "29.000",
     "35.000",
     "23.000",
     "24.000"
    ],
    [
     "Tr36x3",
     "36",
     "3",
     "34.500",
     "36.500",
     "32.500",
     "33.000"
    ],
    [
     "Tr36x6",
     "36",
     "6",
     "33.000",
     "37.000",
     "29.000",
     "30.000"
    ],
    [
     "Tr36x10",
     "36",
     "10",
     "31.000",
     "37.000",
     "25.000",
     "26.000"
    ],
    [
     "Tr38x3",
     "38",
     "3",
     "36.500",
     "38.500",
     "34.500",
     "35.000"
    ],
    [
     "Tr38x7",
     "38",
     "7",
     "34.500",
     "39.000",
     "30.000",
     "31.000"
    ],
    [
     "Tr38x10",
     "38",
     "10",
     "33.000",
     "39.000",
     "27.000",
     "28.000"
    ],
    [
     "Tr40x3",
     "40",
     "3",
     "38.500",
     "40.500",
     "36.500",
     "37.000"
    ],
    [
     "Tr40x7",
     "40",
     "7",
     "36.500",
     "41.000",
     "32.000",
     "33.000"
    ],
    [
     "Tr40x10",
     "40",
     "10",
     "35.000",
     "41.000",
     "29.000",
     "30.000"
    ]
   ]
  }
 },
 "sheet_text": "Trapezoidal lead screw threads Tr10 to Tr40 (ISO 2904 / DIN 103): Tr10x2, Tr12x3, Tr16x4, Tr20x4, Tr24x5, Tr30x6, Tr40x7: pitch, d2, D4, d3, D1 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/trapezoidal-threads-tr10-tr40-iso-2904/  (sheet CC BY 4.0)\nBasis: ISO 2904:2020 sample table (iTeh) with formula checks on every row; fasten.it, Roymech and AmesWeb as comparison; numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Tr is the metric trapezoidal (30 degree flank angle) lead-screw thread: Tr10x2 means 10 mm nominal diameter and 2 mm pitch. For a single-start screw the lead equals the pitch; a multi-start thread has lead = P x starts and is written Tr d x lead (P pitch). The standard's formulas: D1 = d - P, d2 = D2 = d - 0.5 P, D4 = d + 2 ac, d3 = d - P - 2 ac (ac is the crest clearance, which differs by pitch).\n- Numbers: the ISO 2904:2020 sample (iTeh) table for Tr10 to Tr40 (44 d x P combinations); the generator re-checks D1 = d - P, d2 = d - 0.5 P and d3 = d - P - 2 ac on every row (ac = (D4 - d) / 2). AmesWeb's limits tables print the same screw minor and nut major values where compared (Tr10x1.5: d3 8.200, D4 10.300; Tr16x4: d3 11.500; Tr40x7: d3 32.000).\n- Disagreements kept: fasten.it's copy of the table (a cancelled-DIN reproduction) prints Tr10x1.5 with D4 11, d3 8 and D1 7.5, Roymech with D4 11, d3 2.000 and D1 3.000; the ISO 2904 sample and AmesWeb both give D4 10.3, d3 8.2, D1 8.5, which the formulas confirm. fasten.it, Roymech and AmesWeb also list Tr16x3 (and Tr18x3, Tr20x3 on AmesWeb), which the ISO 2904 sample table does not; Tr16x4 is in the ISO sample (and AmesWeb) but fasten.it and Roymech print Tr16x3 in its place. Those rows are not used here.\n- Numbers only, no files: a lead screw's length, ends and start count are chosen by the user, and the helical thread is not a published envelope. For modelled lead screws see the T8 lead screw and the Tr10x2 screw pages.\n- Left out: the external / internal tolerance classes (7e, 7H and so on), the multi-start leads, Tr sizes above 40 mm, ac / H4 / h3 values per pitch (not in the sample).\n\nthread  nominal Ø d, mm  pitch P, mm  pitch Ø d2 = D2, mm  nut major Ø D4, mm  screw minor Ø d3, mm  nut minor Ø D1, mm\nTr10x1.5  10  1.5  9.250  10.300  8.200  8.500\nTr10x2  10  2  9.000  10.500  7.500  8.000\nTr11x2  11  2  10.000  11.500  8.500  9.000\nTr11x3  11  3  9.500  11.500  7.500  8.000\nTr12x2  12  2  11.000  12.500  9.500  10.000\nTr12x3  12  3  10.500  12.500  8.500  9.000\nTr14x2  14  2  13.000  14.500  11.500  12.000\nTr14x3  14  3  12.500  14.500  10.500  11.000\nTr16x2  16  2  15.000  16.500  13.500  14.000\nTr16x4  16  4  14.000  16.500  11.500  12.000\nTr18x2  18  2  17.000  18.500  15.500  16.000\nTr18x4  18  4  16.000  18.500  13.500  14.000\nTr20x2  20  2  19.000  20.500  17.500  18.000\nTr20x4  20  4  18.000  20.500  15.500  16.000\nTr22x3  22  3  20.500  22.500  18.500  19.000\nTr22x5  22  5  19.500  22.500  16.500  17.000\nTr22x8  22  8  18.000  23.000  13.000  14.000\nTr24x3  24  3  22.500  24.500  20.500  21.000\nTr24x5  24  5  21.500  24.500  18.500  19.000\nTr24x8  24  8  20.000  25.000  15.000  16.000\nTr26x3  26  3  24.500  26.500  22.500  23.000\nTr26x5  26  5  23.500  26.500  20.500  21.000\nTr26x8  26  8  22.000  27.000  17.000  18.000\nTr28x3  28  3  26.500  28.500  24.500  25.000\nTr28x5  28  5  25.500  28.500  22.500  23.000\nTr28x8  28  8  24.000  29.000  19.000  20.000\nTr30x3  30  3  28.500  30.500  26.500  27.000\nTr30x6  30  6  27.000  31.000  23.000  24.000\nTr30x10  30  10  25.000  31.000  19.000  20.000\nTr32x3  32  3  30.500  32.500  28.500  29.000\nTr32x6  32  6  29.000  33.000  25.000  26.000\nTr32x10  32  10  27.000  33.000  21.000  22.000\nTr34x3  34  3  32.500  34.500  30.500  31.000\nTr34x6  34  6  31.000  35.000  27.000  28.000\nTr34x10  34  10  29.000  35.000  23.000  24.000\nTr36x3  36  3  34.500  36.500  32.500  33.000\nTr36x6  36  6  33.000  37.000  29.000  30.000\nTr36x10  36  10  31.000  37.000  25.000  26.000\nTr38x3  38  3  36.500  38.500  34.500  35.000\nTr38x7  38  7  34.500  39.000  30.000  31.000\nTr38x10  38  10  33.000  39.000  27.000  28.000\nTr40x3  40  3  38.500  40.500  36.500  37.000\nTr40x7  40  7  36.500  41.000  32.000  33.000\nTr40x10  40  10  35.000  41.000  29.000  30.000\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- iTeh Standards: ISO 2904:2020 sample: ISO metric trapezoidal screw threads, basic dimensions, formulas and the d, P, d2, D4, d3, D1 table (Tr10 to Tr40) — web — Publisher's page; dimensions are facts — https://cdn.standards.iteh.ai/samples/78729/7d158726108b478c889fa887d460ba78/ISO-2904-2020.pdf\n- fasten.it: ISO 2904 (cancelled DIN 103 successor) trapezoidal thread table, reproduced by permission of DIN — web — Publisher's page; dimensions are facts — https://fasten.it/en/Norms/Norm/ISO%202904\n- Roymech: Trapezoidal threads: metric table d, P, d2, D4, d3, D1 — web — Publisher's page; dimensions are facts — https://roymech.org/Useful_Tables/Screws/Trapezoidal.html\n- AmesWeb: Trapezoidal thread chart: external / internal major, pitch, minor diameter limits — web — Publisher's page; dimensions are facts — https://amesweb.info/Screws/trapezoidal-thread-chart.aspx\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=trapezoidal-threads-tr10-tr40-iso-2904\n",
 "sources": [
  {
   "publisher": "iTeh Standards",
   "title": "ISO 2904:2020 sample: ISO metric trapezoidal screw threads, basic dimensions, formulas and the d, P, d2, D4, d3, D1 table (Tr10 to Tr40)",
   "url": "https://cdn.standards.iteh.ai/samples/78729/7d158726108b478c889fa887d460ba78/ISO-2904-2020.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "fasten.it",
   "title": "ISO 2904 (cancelled DIN 103 successor) trapezoidal thread table, reproduced by permission of DIN",
   "url": "https://fasten.it/en/Norms/Norm/ISO%202904",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Roymech",
   "title": "Trapezoidal threads: metric table d, P, d2, D4, d3, D1",
   "url": "https://roymech.org/Useful_Tables/Screws/Trapezoidal.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "AmesWeb",
   "title": "Trapezoidal thread chart: external / internal major, pitch, minor diameter limits",
   "url": "https://amesweb.info/Screws/trapezoidal-thread-chart.aspx",
   "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": [
  "t8-lead-screw",
  "lead-screw-tr10x2-l80-journals-6",
  "lead-screw-and-slide-mechanism",
  "acme-threads-asme-b1-5-1-4-to-2-in",
  "thrust-ball-bearings-51100-series",
  "thrust-ball-bearings-51200-51300-series",
  "ball-screw-end-supports-bk-bf-fk-ff"
 ],
 "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 Tr10x2 thread?",
   "a": "Nominal diameter 10, pitch 2: pitch diameter d2 = 9.000, nut minor D1 = 8.000, screw minor d3 = 7.500, nut major D4 = 10.500 mm (ISO 2904)."
  },
  {
   "q": "What are the dimensions of a Tr12x3 thread?",
   "a": "d2 = 10.500, D1 = 9.000, d3 = 8.500, D4 = 12.500 mm."
  },
  {
   "q": "What are the dimensions of a Tr16x4 thread?",
   "a": "d2 = 14.000, D1 = 12.000, d3 = 11.500, D4 = 16.500 mm."
  },
  {
   "q": "What are the dimensions of a Tr20x4 thread?",
   "a": "d2 = 18.000, D1 = 16.000, d3 = 15.500, D4 = 20.500 mm."
  },
  {
   "q": "What is the formula for the pitch diameter of a Tr thread?",
   "a": "d2 = d - 0.5 P; the nut minor diameter is D1 = d - P (ISO 2904)."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/trapezoidal-threads-tr10-tr40-iso-2904/index.md"
}