{
 "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": "bearing-locknuts-km-din-981",
 "name": "Bearing locknuts KM, DIN 981 / ISO 2982-2: KM0–KM10 (M10×0.75–M50×1.5) outside diameter, width, slots",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the KM locknut (DIN 981) dimensions, from KM0 M10×0.75 to KM10 M50×1.5?",
 "tags": [
  "din 981",
  "km locknut",
  "km nut",
  "bearing locknut",
  "slotted round nut",
  "iso 2982-2",
  "mb tab washer",
  "skf km"
 ],
 "aliases": [
  "km0 locknut dimensions",
  "km4 lock nut m20x1",
  "din 981 km nut size chart",
  "km6 m30x1.5 nut od",
  "bearing lock nut slot width",
  "km10 m50 locknut 70 mm"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 11,
 "url": "https://xemstudio.com/objects/bearing-locknuts-km-din-981/",
 "sheet_txt": "https://xemstudio.com/objects/bearing-locknuts-km-din-981/sheet.txt",
 "sheet": {
  "basis": "Schaeffler and NTN catalogue pages for KM0, KM1, KM2 (main dimensions to DIN 981), Kramp and FAG listings for KM10, KM12, KM15, KM23, and SKF KM series values for the remaining sizes",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Columns: designation, thread G, outside d2, chamfer diameter d1, width B, slot width b, slot depth h. Four slots, 30° chamfer on one face (Schaeffler). Use with MB lock washers (DIN 5406).",
   "Verified on the maker pages read: KM0 (d2 18, d1 13.5, B 4, b 3), KM1 (22, 17, 4, 3, h 2), KM2 (25, 21, 5, 4, h 2), KM10 (70 × 11). KM3–KM9 are SKF catalogue values; check a maker drawing before relying on d1 or h for those.",
   "Files: thread as a plain bore at the major diameter, as for the other nuts on Xem."
  ],
  "table": {
   "columns": [
    "size",
    "thread",
    "d2",
    "d1",
    "B",
    "b",
    "h"
   ],
   "rows": [
    [
     "KM0",
     "M10x0.75",
     "18",
     "13.5",
     "4",
     "3",
     "2"
    ],
    [
     "KM1",
     "M12x1",
     "22",
     "17",
     "4",
     "3",
     "2"
    ],
    [
     "KM2",
     "M15x1",
     "25",
     "21",
     "5",
     "4",
     "2"
    ],
    [
     "KM3",
     "M17x1",
     "28",
     "24",
     "5",
     "4",
     "2"
    ],
    [
     "KM4",
     "M20x1",
     "32",
     "26",
     "6",
     "4",
     "2"
    ],
    [
     "KM5",
     "M25x1.5",
     "38",
     "32",
     "7",
     "5",
     "2"
    ],
    [
     "KM6",
     "M30x1.5",
     "45",
     "38",
     "7",
     "5",
     "2"
    ],
    [
     "KM7",
     "M35x1.5",
     "52",
     "44",
     "8",
     "5",
     "2"
    ],
    [
     "KM8",
     "M40x1.5",
     "58",
     "50",
     "9",
     "6",
     "2.5"
    ],
    [
     "KM9",
     "M45x1.5",
     "65",
     "56",
     "10",
     "6",
     "2.5"
    ],
    [
     "KM10",
     "M50x1.5",
     "70",
     "61",
     "11",
     "6",
     "2.5"
    ]
   ]
  }
 },
 "sheet_text": "Bearing locknuts KM, DIN 981 / ISO 2982-2: KM0–KM10 (M10×0.75–M50×1.5) outside diameter, width, slots — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/bearing-locknuts-km-din-981/  (sheet CC BY 4.0)\nBasis: Schaeffler and NTN catalogue pages for KM0, KM1, KM2 (main dimensions to DIN 981), Kramp and FAG listings for KM10, KM12, KM15, KM23, and SKF KM series values for the remaining sizes\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Columns: designation, thread G, outside d2, chamfer diameter d1, width B, slot width b, slot depth h. Four slots, 30° chamfer on one face (Schaeffler). Use with MB lock washers (DIN 5406).\n- Verified on the maker pages read: KM0 (d2 18, d1 13.5, B 4, b 3), KM1 (22, 17, 4, 3, h 2), KM2 (25, 21, 5, 4, h 2), KM10 (70 × 11). KM3–KM9 are SKF catalogue values; check a maker drawing before relying on d1 or h for those.\n- Files: thread as a plain bore at the major diameter, as for the other nuts on Xem.\n\nsize  thread  d2  d1  B  b  h\nKM0  M10x0.75  18  13.5  4  3  2\nKM1  M12x1  22  17  4  3  2\nKM2  M15x1  25  21  5  4  2\nKM3  M17x1  28  24  5  4  2\nKM4  M20x1  32  26  6  4  2\nKM5  M25x1.5  38  32  7  5  2\nKM6  M30x1.5  45  38  7  5  2\nKM7  M35x1.5  52  44  8  5  2\nKM8  M40x1.5  58  50  9  6  2.5\nKM9  M45x1.5  65  56  10  6  2.5\nKM10  M50x1.5  70  61  11  6  2.5\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Schaeffler: KM0 locknut, main dimensions to DIN 981: G, d2, B, d1, b — web — Publisher's page; dimensions are facts — https://medias-at.schaeffler.com/en/produit/rotary/roulements-et-paliers-lisses/accessoires/ecrou-a-encoches/km0/p/418251\n- Schaeffler: KM2 locknut, main dimensions to DIN 981 — web — Publisher's page; dimensions are facts — https://medias.schaeffler.com/medias/en!hp.ec.br.pr/KM*KM2\n- Acorn Industrial: KM 9 locknut: M45×1.5, 65 mm OD, 10 mm wide — web — Publisher's page; dimensions are facts — https://acorn-ind.co.uk/p/km9-fag\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 11 parts): https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/index.json\nAPI: https://xemstudio.com/api/geometry?object=bearing-locknuts-km-din-981\n",
 "sources": [
  {
   "publisher": "Schaeffler",
   "title": "KM0 locknut, main dimensions to DIN 981: G, d2, B, d1, b",
   "url": "https://medias-at.schaeffler.com/en/produit/rotary/roulements-et-paliers-lisses/accessoires/ecrou-a-encoches/km0/p/418251",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Schaeffler",
   "title": "KM2 locknut, main dimensions to DIN 981",
   "url": "https://medias.schaeffler.com/medias/en!hp.ec.br.pr/KM*KM2",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Acorn Industrial",
   "title": "KM 9 locknut: M45×1.5, 65 mm OD, 10 mm wide",
   "url": "https://acorn-ind.co.uk/p/km9-fag",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "608-bearing",
  "self-aligning-ball-bearings-12xx-13xx-22xx-23xx",
  "retaining-rings-din-471-external"
 ],
 "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": [
  {
   "feature": "thread (plain bore at the major Ø)",
   "exact": "G: M10×0.75 (KM0) to M50×1.5 (KM10)",
   "mates": "shaft thread of the same G; seats against the bearing inner ring or a spacer",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "4 slots on the outside",
   "exact": "b wide × h deep (KM0 3 × 2, KM10 10 × 3)",
   "mates": "hook spanner, and the outer tab of an MB lock washer (DIN 5406, same number) bent into one slot",
   "fit": "designed",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. ISO 286 equivalent: H7/p6 (locational interference) or tighter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. ISO 286 equivalent: H7/g6 or H7/h6.",
  "run": "turns or slides in use: pin in a link, rod through a guide. ISO 286 equivalent: H8/f7 (close running).",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. ISO 286 equivalent: H9/d9 (free running) or looser.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "What thread is a KM0 locknut?",
   "a": "M10 × 0.75, 18 mm outside diameter, 4 mm wide, four 3 × 2 mm slots (DIN 981)."
  },
  {
   "q": "What locks a KM nut?",
   "a": "An MB tab washer to DIN 5406 of the same number (MB0 for KM0) bends into one of the four slots."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "km0",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km0.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km0.stl",
   "note": "KM0 M10x0.75: Ø18 × 4, 4 slots 3×2, thread as Ø10 bore"
  },
  {
   "file": "km1",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km1.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km1.stl",
   "note": "KM1 M12x1: Ø22 × 4, 4 slots 3×2, thread as Ø12 bore"
  },
  {
   "file": "km2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km2.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km2.stl",
   "note": "KM2 M15x1: Ø25 × 5, 4 slots 4×2, thread as Ø15 bore"
  },
  {
   "file": "km3",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km3.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km3.stl",
   "note": "KM3 M17x1: Ø28 × 5, 4 slots 4×2, thread as Ø17 bore"
  },
  {
   "file": "km4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km4.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km4.stl",
   "note": "KM4 M20x1: Ø32 × 6, 4 slots 4×2, thread as Ø20 bore"
  },
  {
   "file": "km5",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km5.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km5.stl",
   "note": "KM5 M25x1.5: Ø38 × 7, 4 slots 5×2, thread as Ø25 bore"
  },
  {
   "file": "km6",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km6.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km6.stl",
   "note": "KM6 M30x1.5: Ø45 × 7, 4 slots 5×2, thread as Ø30 bore"
  },
  {
   "file": "km7",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km7.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km7.stl",
   "note": "KM7 M35x1.5: Ø52 × 8, 4 slots 5×2, thread as Ø35 bore"
  },
  {
   "file": "km8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km8.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km8.stl",
   "note": "KM8 M40x1.5: Ø58 × 9, 4 slots 6×2.5, thread as Ø40 bore"
  },
  {
   "file": "km9",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km9.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km9.stl",
   "note": "KM9 M45x1.5: Ø65 × 10, 4 slots 6×2.5, thread as Ø45 bore"
  },
  {
   "file": "km10",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km10.step",
   "stl": "https://xemstudio.com/files/hardware/bearing-locknuts-km-din-981/km10.stl",
   "note": "KM10 M50x1.5: Ø70 × 11, 4 slots 6×2.5, thread as Ø50 bore"
  }
 ],
 "markdown": "https://xemstudio.com/objects/bearing-locknuts-km-din-981/index.md"
}