{
 "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": "hydraulic-quick-couplers-iso-16028-iso-7241",
 "name": "Hydraulic quick couplers: ISO 16028 flat-face and ISO 7241-A / B plug diameters (J) by size, 1/4 to 1 in",
 "kind": "standard",
 "category": "Tri-clamp & pipe",
 "group": "Pipe, tube & threads",
 "year": null,
 "question": "What is the plug diameter of an ISO 16028 flat-face or ISO 7241-A hydraulic quick coupler, by size?",
 "tags": [
  "quick coupler",
  "quick disconnect",
  "flat face coupler",
  "flush face coupler",
  "iso 16028",
  "iso 7241",
  "iso a",
  "iso b",
  "hydraulic coupler",
  "skid steer coupler",
  "ball lock",
  "hydraulic",
  "tool"
 ],
 "aliases": [
  "iso 16028 plug dimensions",
  "flat face coupler 1/2 plug diameter",
  "iso 7241-a 1/2 coupler dimensions",
  "iso 16028 3/8 flat face coupler size",
  "hydraulic quick coupler plug diameter chart",
  "flat face coupler sizes",
  "iso a vs iso b quick coupler",
  "skid steer flat face coupler 3/4 dimensions",
  "iso 7241 b 3/8 plug diameter",
  "faster ffh plug diameter",
  "stucchi firg dimensions",
  "flush face coupler 5/8 size"
 ],
 "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/hydraulic-quick-couplers-iso-16028-iso-7241/",
 "sheet_txt": "https://xemstudio.com/objects/hydraulic-quick-couplers-iso-16028-iso-7241/sheet.txt",
 "sheet": {
  "basis": "OMFB's quick-coupling tables (J), Stucchi's flat face A / FIRG / FL / FIRG Q tables (J), Flowfit's ISO 16028 table (Ød) and Parker's WK-MK112 catalog (series and threads); numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Quick-coupler families: ISO 16028 is the flat-face coupling (the 'flush face' coupler on skid-steer and ag hydraulics: a flat plug nose, no poppet to trap dirt); ISO 7241 (parts 1 and 2; series A and B) is the ball-lock poppet coupling; the numbers here are the male plug (nipple) body diameter that the coupler's ball lock grips, because that is the interface diameter a designer needs. Plug diameter is the letter J in OMFB's and Stucchi's tables (OMFB's text explains only J, as 'male Ø for ball-lock types'; Stucchi's sheet does not define its letters) and Ød on male rows in Flowfit's table (letters not defined there). The three sources agree on the same plug diameters (within 0.05 mm: 16.1 / 16.15, 19.7 / 19.75, 24.5, 27, 30 / 29.95, 36), so J and Ød are the same dimension.",
   "ISO 16028 rows: 1/4 in (ISO size 6.3) 16.1 mm, 3/8 in (10) 19.7, 1/2 in (12.5) 24.5, 5/8 in (16) 27.0, 3/4 in (19) 30.0, 1 in (25) 36.0 (Stucchi's Flat Face 'A' series, whose sheet says it is in accordance with ISO 16028). Sizes 1/8 (11.6), 1 1/4 (44.0), 1 1/2 (57.0) and 2 in (73.0) are in Stucchi's tables with no ISO size printed, and are not claimed as ISO 16028 sizes here. Naming differs by maker: Stucchi calls the 3/4 in size ISO size 19, OMFB's dash 12 is DN 20 and Flowfit's is DN 19; the plug diameter is the same (30 / 29.95 mm). OMFB's note says only the G 1/2 size of one series is compatible with ISO 7241-A.",
   "ISO 7241 rows: J from OMFB's MB series A and B tables (and Stucchi's BIR series for A, which prints the same J for dash 06 to 20). The page prints no J for ISO 7241 in other makers' series, and no ISO 7241 plug groove, lanyard groove, overall length or hex values (only 'HEX. B / C' as drawn). Parker's WK-MK112 catalog lists its 60 series (ISO 7241 series B), 6600 series (ISO 7241 series A) and FEM / FEC series (ISO 16028) body sizes 1/8 to 1 in with NPT, ORB (SAE O-ring boss) and BSPP threads but no interface dimensions, so it is cited for what threads each series comes in, not for diameters.",
   "Left out, no file: a plug body is not just a diameter: the ball-lock groove, the poppet or flat-face nose, and the lengths are drawn in the standard and in makers' dimensioned drawings, none of which came through as numbers; an invented plug would not be a standard part. The tables give the diameters to bore a socket or a hole around. Overall lengths per maker series (Stucchi B to I letters, OMFB B to F, Flowfit C) are published by the makers and not mixed here because their letters are undefined and the series differ.",
   "Not the same as air couplers: for pneumatic plug profiles (industrial M / H / G, Tru-Flate, ARO, European) see air-quick-coupler-plug-profiles; for cam-and-groove hose couplings see camlock-couplings. McMaster-Carr sells ISO A series (ISO 7241-A) hydraulic couplings with per-part STEP; its category page is linked, not copied. Stucchi, OMFB, Parker and Flowfit catalogs are linked as the maker sources."
  ],
  "table": {
   "columns": [
    "standard",
    "size",
    "ISO size / DN",
    "plug Ø J (Stucchi Flat Face A, mm)",
    "Flowfit Ød (mm)",
    "OMFB J (mm)"
   ],
   "rows": [
    [
     "ISO 16028 flat face",
     "1/8 in",
     "—",
     "11.6",
     "—",
     "—"
    ],
    [
     "ISO 16028 flat face",
     "1/4 in",
     "6.3",
     "16.1",
     "16.15 (DN 6.3)",
     "—"
    ],
    [
     "ISO 16028 flat face",
     "3/8 in",
     "10.0",
     "19.7",
     "19.75 (DN 10)",
     "19.7 (dash 06, DN 10: Stucchi FIRG, DNP PLT1, Faster FFH, MB F)"
    ],
    [
     "ISO 16028 flat face",
     "1/2 in",
     "12.5",
     "24.5",
     "24.5 (DN 12.5)",
     "24.5 (dash 08, DN 12.5)"
    ],
    [
     "ISO 16028 flat face",
     "5/8 in",
     "16.0",
     "27.0",
     "27 (DN 16)",
     "27 (dash 10, DN 16)"
    ],
    [
     "ISO 16028 flat face",
     "3/4 in",
     "19.0",
     "30.0",
     "29.95 (DN 19)",
     "30 (dash 12, DN 20)"
    ],
    [
     "ISO 16028 flat face",
     "1 in",
     "25.0",
     "36.0",
     "36 (DN 25)",
     "36 (dash 16, DN 25)"
    ],
    [
     "ISO 16028 flat face",
     "1 1/4 in",
     "—",
     "44.0",
     "—",
     "—"
    ],
    [
     "ISO 16028 flat face",
     "1 1/2 in",
     "—",
     "57.0",
     "—",
     "57 (dash 24, DN 37.5: Stucchi FIRG)"
    ],
    [
     "ISO 16028 flat face",
     "2 in",
     "—",
     "73.0",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A (OMFB MB series A; Stucchi BIR)",
     "3/8 in (dash 06)",
     "10 mm",
     "17.3",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A",
     "1/2 in (dash 08)",
     "12.5 mm",
     "20.5",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A",
     "3/4 in (dash 12)",
     "20 mm",
     "29.1",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A",
     "1 in (dash 16)",
     "25 mm",
     "34.3",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A",
     "1 1/4 in (dash 20)",
     "31.5 mm",
     "45",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 A",
     "1 1/2 in (dash 24)",
     "37.5 mm",
     "55 (OMFB MB A only)",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 B (OMFB MB series B)",
     "3/8 in (dash 06)",
     "10 mm",
     "19.1",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 B",
     "1/2 in (dash 08)",
     "12.5 mm",
     "23.5",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 B",
     "3/4 in (dash 12)",
     "20 mm",
     "31.4",
     "—",
     "—"
    ],
    [
     "ISO 7241-1 B",
     "1 in (dash 16)",
     "25 mm",
     "37.7",
     "—",
     "—"
    ]
   ]
  }
 },
 "sheet_text": "Hydraulic quick couplers: ISO 16028 flat-face and ISO 7241-A / B plug diameters (J) by size, 1/4 to 1 in — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/hydraulic-quick-couplers-iso-16028-iso-7241/  (sheet CC BY 4.0)\nBasis: OMFB's quick-coupling tables (J), Stucchi's flat face A / FIRG / FL / FIRG Q tables (J), Flowfit's ISO 16028 table (Ød) and Parker's WK-MK112 catalog (series and threads); numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Quick-coupler families: ISO 16028 is the flat-face coupling (the 'flush face' coupler on skid-steer and ag hydraulics: a flat plug nose, no poppet to trap dirt); ISO 7241 (parts 1 and 2; series A and B) is the ball-lock poppet coupling; the numbers here are the male plug (nipple) body diameter that the coupler's ball lock grips, because that is the interface diameter a designer needs. Plug diameter is the letter J in OMFB's and Stucchi's tables (OMFB's text explains only J, as 'male Ø for ball-lock types'; Stucchi's sheet does not define its letters) and Ød on male rows in Flowfit's table (letters not defined there). The three sources agree on the same plug diameters (within 0.05 mm: 16.1 / 16.15, 19.7 / 19.75, 24.5, 27, 30 / 29.95, 36), so J and Ød are the same dimension.\n- ISO 16028 rows: 1/4 in (ISO size 6.3) 16.1 mm, 3/8 in (10) 19.7, 1/2 in (12.5) 24.5, 5/8 in (16) 27.0, 3/4 in (19) 30.0, 1 in (25) 36.0 (Stucchi's Flat Face 'A' series, whose sheet says it is in accordance with ISO 16028). Sizes 1/8 (11.6), 1 1/4 (44.0), 1 1/2 (57.0) and 2 in (73.0) are in Stucchi's tables with no ISO size printed, and are not claimed as ISO 16028 sizes here. Naming differs by maker: Stucchi calls the 3/4 in size ISO size 19, OMFB's dash 12 is DN 20 and Flowfit's is DN 19; the plug diameter is the same (30 / 29.95 mm). OMFB's note says only the G 1/2 size of one series is compatible with ISO 7241-A.\n- ISO 7241 rows: J from OMFB's MB series A and B tables (and Stucchi's BIR series for A, which prints the same J for dash 06 to 20). The page prints no J for ISO 7241 in other makers' series, and no ISO 7241 plug groove, lanyard groove, overall length or hex values (only 'HEX. B / C' as drawn). Parker's WK-MK112 catalog lists its 60 series (ISO 7241 series B), 6600 series (ISO 7241 series A) and FEM / FEC series (ISO 16028) body sizes 1/8 to 1 in with NPT, ORB (SAE O-ring boss) and BSPP threads but no interface dimensions, so it is cited for what threads each series comes in, not for diameters.\n- Left out, no file: a plug body is not just a diameter: the ball-lock groove, the poppet or flat-face nose, and the lengths are drawn in the standard and in makers' dimensioned drawings, none of which came through as numbers; an invented plug would not be a standard part. The tables give the diameters to bore a socket or a hole around. Overall lengths per maker series (Stucchi B to I letters, OMFB B to F, Flowfit C) are published by the makers and not mixed here because their letters are undefined and the series differ.\n- Not the same as air couplers: for pneumatic plug profiles (industrial M / H / G, Tru-Flate, ARO, European) see air-quick-coupler-plug-profiles; for cam-and-groove hose couplings see camlock-couplings. McMaster-Carr sells ISO A series (ISO 7241-A) hydraulic couplings with per-part STEP; its category page is linked, not copied. Stucchi, OMFB, Parker and Flowfit catalogs are linked as the maker sources.\n\nstandard  size  ISO size / DN  plug Ø J (Stucchi Flat Face A, mm)  Flowfit Ød (mm)  OMFB J (mm)\nISO 16028 flat face  1/8 in  —  11.6  —  —\nISO 16028 flat face  1/4 in  6.3  16.1  16.15 (DN 6.3)  —\nISO 16028 flat face  3/8 in  10.0  19.7  19.75 (DN 10)  19.7 (dash 06, DN 10: Stucchi FIRG, DNP PLT1, Faster FFH, MB F)\nISO 16028 flat face  1/2 in  12.5  24.5  24.5 (DN 12.5)  24.5 (dash 08, DN 12.5)\nISO 16028 flat face  5/8 in  16.0  27.0  27 (DN 16)  27 (dash 10, DN 16)\nISO 16028 flat face  3/4 in  19.0  30.0  29.95 (DN 19)  30 (dash 12, DN 20)\nISO 16028 flat face  1 in  25.0  36.0  36 (DN 25)  36 (dash 16, DN 25)\nISO 16028 flat face  1 1/4 in  —  44.0  —  —\nISO 16028 flat face  1 1/2 in  —  57.0  —  57 (dash 24, DN 37.5: Stucchi FIRG)\nISO 16028 flat face  2 in  —  73.0  —  —\nISO 7241-1 A (OMFB MB series A; Stucchi BIR)  3/8 in (dash 06)  10 mm  17.3  —  —\nISO 7241-1 A  1/2 in (dash 08)  12.5 mm  20.5  —  —\nISO 7241-1 A  3/4 in (dash 12)  20 mm  29.1  —  —\nISO 7241-1 A  1 in (dash 16)  25 mm  34.3  —  —\nISO 7241-1 A  1 1/4 in (dash 20)  31.5 mm  45  —  —\nISO 7241-1 A  1 1/2 in (dash 24)  37.5 mm  55 (OMFB MB A only)  —  —\nISO 7241-1 B (OMFB MB series B)  3/8 in (dash 06)  10 mm  19.1  —  —\nISO 7241-1 B  1/2 in (dash 08)  12.5 mm  23.5  —  —\nISO 7241-1 B  3/4 in (dash 12)  20 mm  31.4  —  —\nISO 7241-1 B  1 in (dash 16)  25 mm  37.7  —  —\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- OMFB (quick couplings catalogue): MB series A / B (ISO 7241-1) and ISO 16028 flat face: dash, DN, thread, pressure, J, B to F (and Stucchi, DNP, Faster, MB F series tables) — web — Maker catalogue; numbers only. Only J is defined in the text — https://www.omfb.com/catalog/media/ARXIVAR_WEB/99711900010.pdf\n- Stucchi (quick disconnect catalog, hosted by Hydraquip): Flat face A, FIRG, FL and FIRG Q series (ISO 16028): body size, port, B to J, ISO size, weight — web — Maker catalogue; numbers only. The letters are not defined in the text; B and C are drawn as hex sizes — https://www.hydraquip.com/wp-content/uploads/2018/02/stucchi-quick-disconnect-catalog.pdf\n- Flowfit: ISO 16028 flat face couplings (carbon steel, metric): DN, PN, ØA, C, Ød, ch, ØM — web — Maker catalogue; numbers only. The page does not define its letters — https://www.flowfitonline.com/uploads/PDFproducts/03-10-flat-face-21-6.pdf\n- Parker (Hydraulic quick coupler catalog WK-MK112): 60 Series ISO 7241 series B, 6600 Series ISO 7241 series A, FEM / FEC ISO 16028: body sizes and threads — web — Maker catalogue; numbers only — https://www.parker.com/content/dam/Parker-com/Literature/Canada/Canada-Support-Assets/WK-MK112-Hydraulic-Quick-Coupler-Sept-2017.pdf\n- McMaster-Carr: ISO A series couplings (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/iso-a-series-couplings\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=hydraulic-quick-couplers-iso-16028-iso-7241\n",
 "sources": [
  {
   "publisher": "OMFB (quick couplings catalogue)",
   "title": "MB series A / B (ISO 7241-1) and ISO 16028 flat face: dash, DN, thread, pressure, J, B to F (and Stucchi, DNP, Faster, MB F series tables)",
   "url": "https://www.omfb.com/catalog/media/ARXIVAR_WEB/99711900010.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker catalogue; numbers only. Only J is defined in the text",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Stucchi (quick disconnect catalog, hosted by Hydraquip)",
   "title": "Flat face A, FIRG, FL and FIRG Q series (ISO 16028): body size, port, B to J, ISO size, weight",
   "url": "https://www.hydraquip.com/wp-content/uploads/2018/02/stucchi-quick-disconnect-catalog.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker catalogue; numbers only. The letters are not defined in the text; B and C are drawn as hex sizes",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Flowfit",
   "title": "ISO 16028 flat face couplings (carbon steel, metric): DN, PN, ØA, C, Ød, ch, ØM",
   "url": "https://www.flowfitonline.com/uploads/PDFproducts/03-10-flat-face-21-6.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker catalogue; numbers only. The page does not define its letters",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Parker (Hydraulic quick coupler catalog WK-MK112)",
   "title": "60 Series ISO 7241 series B, 6600 Series ISO 7241 series A, FEM / FEC ISO 16028: body sizes and threads",
   "url": "https://www.parker.com/content/dam/Parker-com/Literature/Canada/Canada-Support-Assets/WK-MK112-Hydraulic-Quick-Coupler-Sept-2017.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker catalogue; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "ISO A series couplings (free STEP/IGES per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/iso-a-series-couplings",
   "formats": [
    "STEP",
    "IGES",
    "PDF"
   ],
   "license": "McMaster-Carr site terms: personal design use, no redistribution",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "air-quick-coupler-plug-profiles",
  "camlock-couplings",
  "sae-j1926-iso-11926-o-ring-boss-ports",
  "an-jic-37-degree-flare-fittings",
  "orfs-sae-j1453-o-ring-face-seal-ends",
  "iso-1179-bspp-ports-and-bonded-seals"
 ],
 "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 is the plug diameter of a 1/2 in ISO 16028 flat-face coupler?",
   "a": "24.5 mm: Stucchi's Flat Face A series J, Flowfit's Ød (DN 12.5) and OMFB's J (dash 08) all print 24.5."
  },
  {
   "q": "What is the difference between ISO 7241-A and ISO 7241-B?",
   "a": "They are different plug interfaces: OMFB's 3/8 in plug is 17.3 mm for series A and 19.1 mm for series B (1/2 in: 20.5 vs 23.5), so A and B couplers do not interchange."
  },
  {
   "q": "Is a 3/4 in flat-face coupler DN 19 or DN 20?",
   "a": "Makers differ: Stucchi prints ISO size 19.0, Flowfit DN 19, OMFB DN 20 for the same 29.95 to 30 mm plug."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/hydraulic-quick-couplers-iso-16028-iso-7241/index.md"
}