{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "tri-clamp-male-npt-adapters",
 "name": "Tri-clamp × male NPT adapters (21MP style): ½ to 4 in",
 "kind": "standard",
 "category": "Hardware",
 "group": "Sanitary clamp fittings",
 "year": null,
 "question": "How long is a tri-clamp to male NPT adapter?",
 "tags": [
  "adapter",
  "npt",
  "male npt",
  "21mp",
  "threaded adapter",
  "sanitary",
  "tri-clamp",
  "clamp fitting",
  "brewing",
  "homebrew"
 ],
 "aliases": [
  "tri clamp to npt",
  "tri clamp to male npt adapter",
  "21mp adapter dimensions",
  "1.5 tri clamp to 1/2 npt",
  "tri clamp npt adapter stl"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 10,
 "url": "https://xemstudio.com/objects/tri-clamp-male-npt-adapters/",
 "sheet_txt": "https://xemstudio.com/objects/tri-clamp-male-npt-adapters/sheet.txt",
 "sheet": {
  "basis": "Face-to-end A per Dixon T21MP; NPT envelope (major diameter over L2) per ASME B1.20.1; bore the smaller of the clamp bore and the Sch 40 bore",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Clamp face one end, male pipe thread the other. Threads are drawn as plain cylinders at the major diameter over the effective length L2; cut or chase the thread on the part, or print the envelope as a gauge.",
   "Only sizes with a published A are drawn.",
   "Every clamp face is the ISO 2852 profile used across this site: 2.85 mm rim, flat face with the gasket groove (K 1.6 deep, R3 1.2 bottom, 23° walls, P2 0.8 edges) on C2, 20° back cone. Flange C3 / groove C2 / tube OD × wall, mm: ½–¾ in 25.0 / 20.4 (derived) / 12.7–19.05 × 1.65; 1–1½ in 50.5 / 43.5 / 25.4–38.1 × 1.65; 2 in 64.0 / 56.5 / 50.8 × 1.65; 2½ in 77.5 / 70.5 / 63.5 × 1.65; 3 in 91.0 / 83.5 / 76.2 × 1.65; 4 in 119.0 / 110.0 / 101.6 × 2.11; 6 in 166.9 (6.570 in) / 156.5 / 152.4 × 2.77; 8 in 217.7 (8.570 in) / 207.0 / 203.2 × 2.77; 10 in 268.5 / 261.0 / 254.0 × 3.40; 12 in 319.3 / 311.8 / 304.8 × 3.40."
  ],
  "table": {
   "columns": [
    "clamp_in",
    "npt",
    "A_in",
    "A_mm",
    "thread_major_mm",
    "L2_mm"
   ],
   "rows": [
    [
     "½",
     "¼",
     2,
     50.8,
     13.72,
     10.2
    ],
    [
     "½",
     "½",
     1.63,
     41.4,
     21.34,
     13.6
    ],
    [
     "½",
     "¾",
     2,
     50.8,
     26.67,
     13.9
    ],
    [
     "¾",
     "¾",
     1.79,
     45.5,
     26.67,
     13.9
    ],
    [
     "1",
     "½",
     2.19,
     55.6,
     21.34,
     13.6
    ],
    [
     "1",
     "1",
     2.25,
     57.1,
     33.4,
     17.3
    ],
    [
     "2",
     "2",
     2.64,
     67.1,
     60.33,
     19.22
    ],
    [
     "2½",
     "2½",
     2.88,
     73.2,
     73.03,
     28.89
    ],
    [
     "3",
     "3",
     3.07,
     78,
     88.9,
     30.48
    ],
    [
     "4",
     "4",
     3.16,
     80.3,
     114.3,
     33.02
    ]
   ]
  }
 },
 "sheet_text": "Tri-clamp × male NPT adapters (21MP style): ½ to 4 in — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/tri-clamp-male-npt-adapters/  (CC BY 4.0)\nBasis: Face-to-end A per Dixon T21MP; NPT envelope (major diameter over L2) per ASME B1.20.1; bore the smaller of the clamp bore and the Sch 40 bore\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Clamp face one end, male pipe thread the other. Threads are drawn as plain cylinders at the major diameter over the effective length L2; cut or chase the thread on the part, or print the envelope as a gauge.\n- Only sizes with a published A are drawn.\n- Every clamp face is the ISO 2852 profile used across this site: 2.85 mm rim, flat face with the gasket groove (K 1.6 deep, R3 1.2 bottom, 23° walls, P2 0.8 edges) on C2, 20° back cone. Flange C3 / groove C2 / tube OD × wall, mm: ½–¾ in 25.0 / 20.4 (derived) / 12.7–19.05 × 1.65; 1–1½ in 50.5 / 43.5 / 25.4–38.1 × 1.65; 2 in 64.0 / 56.5 / 50.8 × 1.65; 2½ in 77.5 / 70.5 / 63.5 × 1.65; 3 in 91.0 / 83.5 / 76.2 × 1.65; 4 in 119.0 / 110.0 / 101.6 × 2.11; 6 in 166.9 (6.570 in) / 156.5 / 152.4 × 2.77; 8 in 217.7 (8.570 in) / 207.0 / 203.2 × 2.77; 10 in 268.5 / 261.0 / 254.0 × 3.40; 12 in 319.3 / 311.8 / 304.8 × 3.40.\n\nclamp_in  npt  A_in  A_mm  thread_major_mm  L2_mm\n½  ¼  2.0  50.8  13.72  10.2\n½  ½  1.63  41.4  21.34  13.6\n½  ¾  2.0  50.8  26.67  13.9\n¾  ¾  1.79  45.5  26.67  13.9\n1  ½  2.19  55.6  21.34  13.6\n1  1  2.25  57.1  33.4  17.3\n2  2  2.64  67.1  60.33  19.22\n2½  2½  2.88  73.2  73.03  28.89\n3  3  3.07  78.0  88.9  30.48\n4  4  3.16  80.3  114.3  33.02\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Dixon: Clamp × male NPT (T21MP) and clamp × female NPT (T22MP) adapters: A per size — PDF — publisher's catalogue; dimensions cited — https://api.dixonvalve.com/en/media/1490003\n- ASME: B1.20.1 Pipe threads, general purpose (NPT): major diameter, L2, tap drill; B16.11 forged fittings (Class 3000 couplings); B36.10 Sch 40 bore — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/b1-20-1-pipe-threads-general-purpose-inch\n- Rubber Fab: Tri-Clamp gasket dimensional chart: gasket ID, OD and bead diameter per size (2 in bead 2.22 in / 56.50 mm, 1.5 in 1.71 / 43.50, 3 in 3.29 / 83.50) — PDF — maker chart; dimensions are facts [verify license at link] — https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 10 parts): https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/index.json\nAPI: https://xemstudio.com/api/geometry?object=tri-clamp-male-npt-adapters\n",
 "sources": [
  {
   "publisher": "Dixon",
   "title": "Clamp × male NPT (T21MP) and clamp × female NPT (T22MP) adapters: A per size",
   "url": "https://api.dixonvalve.com/en/media/1490003",
   "formats": [
    "PDF"
   ],
   "license": "publisher's catalogue; dimensions cited",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ASME",
   "title": "B1.20.1 Pipe threads, general purpose (NPT): major diameter, L2, tap drill; B16.11 forged fittings (Class 3000 couplings); B36.10 Sch 40 bore",
   "url": "https://www.asme.org/codes-standards/find-codes-standards/b1-20-1-pipe-threads-general-purpose-inch",
   "formats": [
    "standard"
   ],
   "license": "ASME; dimensions are facts",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Rubber Fab",
   "title": "Tri-Clamp gasket dimensional chart: gasket ID, OD and bead diameter per size (2 in bead 2.22 in / 56.50 mm, 1.5 in 1.71 / 43.50, 3 in 3.29 / 83.50)",
   "url": "https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf",
   "formats": [
    "PDF"
   ],
   "license": "maker chart; dimensions are facts",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "tri-clamp-female-npt-adapters",
  "tri-clamp-hose-barb-adapters",
  "tri-clamp-ported-end-caps"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. 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.",
 "mating": [],
 "faq": [
  {
   "q": "How long is a 2 in tri-clamp × 2 in MNPT adapter?",
   "a": "2.64 in (67.1 mm) from the clamp face to the end of the thread."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "male-npt-0.5in-x-1-4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-1-4.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-1-4.stl",
   "note": "½ in clamp × ¼ MNPT: 2.0 in face to thread end; thread envelope Ø13.72 × 10.2 (L2)"
  },
  {
   "file": "male-npt-0.5in-x-1-2",
   "formats": [
    "step",
    "stl"
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   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-1-2.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-1-2.stl",
   "note": "½ in clamp × ½ MNPT: 1.63 in face to thread end; thread envelope Ø21.34 × 13.6 (L2)"
  },
  {
   "file": "male-npt-0.5in-x-3-4",
   "formats": [
    "step",
    "stl"
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   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-3-4.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.5in-x-3-4.stl",
   "note": "½ in clamp × ¾ MNPT: 2.0 in face to thread end; thread envelope Ø26.67 × 13.9 (L2)"
  },
  {
   "file": "male-npt-0.75in-x-3-4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.75in-x-3-4.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-0.75in-x-3-4.stl",
   "note": "¾ in clamp × ¾ MNPT: 1.79 in face to thread end; thread envelope Ø26.67 × 13.9 (L2)"
  },
  {
   "file": "male-npt-1in-x-1-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-1in-x-1-2.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-1in-x-1-2.stl",
   "note": "1 in clamp × ½ MNPT: 2.19 in face to thread end; thread envelope Ø21.34 × 13.6 (L2)"
  },
  {
   "file": "male-npt-1in-x-1",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-1in-x-1.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-1in-x-1.stl",
   "note": "1 in clamp × 1 MNPT: 2.25 in face to thread end; thread envelope Ø33.4 × 17.3 (L2)"
  },
  {
   "file": "male-npt-2in-x-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-2in-x-2.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-2in-x-2.stl",
   "note": "2 in clamp × 2 MNPT: 2.64 in face to thread end; thread envelope Ø60.33 × 19.22 (L2)"
  },
  {
   "file": "male-npt-2.5in-x-2-1-2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-2.5in-x-2-1-2.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-2.5in-x-2-1-2.stl",
   "note": "2½ in clamp × 2½ MNPT: 2.88 in face to thread end; thread envelope Ø73.03 × 28.89 (L2)"
  },
  {
   "file": "male-npt-3in-x-3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-3in-x-3.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-3in-x-3.stl",
   "note": "3 in clamp × 3 MNPT: 3.07 in face to thread end; thread envelope Ø88.9 × 30.48 (L2)"
  },
  {
   "file": "male-npt-4in-x-4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-4in-x-4.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-male-npt-adapters/male-npt-4in-x-4.stl",
   "note": "4 in clamp × 4 MNPT: 3.16 in face to thread end; thread envelope Ø114.3 × 33.02 (L2)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/tri-clamp-male-npt-adapters/index.md"
}