{
 "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": "rack-cage-nuts-and-rail-holes",
 "name": "19-inch rack rail holes (EIA-310: 15.875 / 15.875 / 12.7 mm pitch, 465.1 mm spacing, 9.5 mm square) and M5 / M6 / 10-32 / 12-24 cage nuts + 2U square-hole rail gauge",
 "kind": "standard",
 "category": "Hardware",
 "group": "Fasteners",
 "year": null,
 "question": "What size is the square hole in a server rack rail, and what size are M5, M6, 10-32 and 12-24 cage nuts?",
 "tags": [
  "cage nut",
  "rack cage nut",
  "server rack screws",
  "square hole rack",
  "m6 cage nut",
  "10-32 cage nut",
  "12-24 cage nut",
  "m5 cage nut",
  "eia-310",
  "19 inch rack hole",
  "rack rail hole spacing",
  "rack mount nut"
 ],
 "aliases": [
  "cage nut dimensions",
  "server rack square hole size",
  "m6 cage nut size",
  "10-32 cage nut dimensions",
  "rack rail hole spacing mm",
  "eia 310 hole pattern",
  "cage nut square hole 9.5 mm",
  "rack unit hole spacing 15.875",
  "m5 cage nut dimensions",
  "19 inch rack hole size",
  "12-24 cage nut size",
  "cage nut panel thickness",
  "rack screw size 10-32 vs m6"
 ],
 "overall_mm": {
  "length": 88.9,
  "width": 25,
  "height": 2
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/rack-cage-nuts-and-rail-holes/",
 "sheet_txt": "https://xemstudio.com/objects/rack-cage-nuts-and-rail-holes/sheet.txt",
 "sheet": {
  "basis": "EIA-310 hole pattern as printed by Digital Loggers, Schneider Electric and Rack Solutions; cage nut sizes from RS PRO, Essentra, StarTech, Rapid Electronics (R-TECH), Hammond, HDBOLT and nVent Hoffman; one 2U rail gauge file",
  "overall_mm": {
   "length": 88.9,
   "width": 25,
   "height": 2
  },
  "notes": [
   "Rail data: the vertical hole pitch repeats 5/8, 5/8, 1/2 in (15.875, 15.875, 12.7 mm) with a U of 44.45 mm starting in the middle of the 1/2 in gap; the hole columns of the two rails are 465.1 mm apart (18 5/16 in); equipment clears 450 mm between rails. These are the figures three makers print as EIA-310 (Schneider cites EIA/ECA-310-E). None of the three pages gives the hole sizes, the rail flange width or the thickness, and the standard itself was not read, so the 9.5 mm square hole comes from the cage nut sheets.",
   "Square hole: 9.5 mm (RS PRO's description, HDBOLT 'most common'), 9.53 mm (RS PRO's attribute table) and 0.375 in = 9.54 mm (Hammond). Those are the same 3/8 in rounded; the file uses 9.525 mm. Round-hole and tapped-hole rails (for 10-32, 12-24 and M6 screws) also exist; no source read gives their hole sizes, so they are not on this page.",
   "Cage nut body sizes are what each seller prints and they are not a standard: Essentra M5 12.5 × 9.0 mm and M6 12.5 × 9.3 mm (overall length × height), M8 16.3 × 11.6 mm; StarTech M5 about 13 × 13 × 9 mm; RS PRO M6 15 mm overall width; RS PRO prints panel thickness 0.8 – 6 mm, Rapid's R-TECH parts print panel ranges 0.7 – 1.6 and 1.7 – 2.5 mm. Rapid's sheet lists eight dimension values (A to H) without a mapping and they are shown as printed. The cage nuts snap into the square hole from the rail face. Hammond's datasheet calls out 10-32, 12-24 and M6 cage nuts for 0.375 in (9.54 mm) holes and gives torque figures that conflict between versions, so none is shown.",
   "File: a 2U strip of rail face, 25 mm wide, 2 mm thick, with six 9.525 mm square holes on the 15.875 / 15.875 / 12.7 mm pitch, U boundaries in the middle of the 12.7 mm gaps. Width and thickness are Xem's choices. It is a hole gauge for a cage nut or square-hole cutout, not a model of a rail. Rack ears and unit heights: rack-19in-ears. Cage nuts have a clip and a captive threaded plate; no model is drawn because the clip geometry is not published as numbers."
  ],
  "table": {
   "columns": [
    "part",
    "item",
    "thread",
    "dimension / value",
    "source / note"
   ],
   "rows": [
    [
     "rail",
     "rack unit (U) height",
     "—",
     "44.45 mm (1.75 in)",
     "Schneider; Rack Solutions; Digital Loggers (1.75 in)"
    ],
    [
     "rail",
     "vertical hole pitch within a U",
     "—",
     "5/8, 5/8, 1/2 in = 15.875, 15.875, 12.7 mm (Schneider prints 15.9, 15.9, 12.7)",
     "Digital Loggers prints 1/2, 5/8, 5/8 in repeating; Schneider 5/8, 5/8, 1/2"
    ],
    [
     "rail",
     "where a U starts",
     "—",
     "at the middle of the 1/2 in (12.7 mm) gap between holes; a 1U device covers three holes with the notched hole in the middle",
     "Rack Solutions; Schneider"
    ],
    [
     "rail",
     "horizontal hole spacing (between the two rails' hole columns)",
     "—",
     "18 5/16 in = 465.1 mm (18.312 in); Schneider ±1.6 mm",
     "Digital Loggers; Rack Solutions; Schneider"
    ],
    [
     "rail",
     "clearance between rails (minimum) / outside edges of rails (minimum)",
     "—",
     "450 mm (17.72 in) / 483.4 mm",
     "Digital Loggers; Schneider"
    ],
    [
     "rail",
     "equipment front panel width",
     "—",
     "19 in (482.6 mm)",
     "Digital Loggers; Rack Solutions (19 in)"
    ],
    [
     "rail",
     "square hole size",
     "—",
     "9.5 mm (RS description, HDBOLT) / 9.53 mm (RS attribute) / 0.375 in = 9.54 mm (Hammond)",
     "all three are 3/8 in rounded three ways; 9.525 mm is used for the file"
    ],
    [
     "rail",
     "round hole, tapped hole, rail flange width and thickness",
     "—",
     "no published value found in the pages read",
     "—"
    ],
    [
     "cage nut",
     "M6, RS PRO",
     "M6",
     "overall width 15 mm; cutout 9.53 × 9.53 mm; for panel 0.8 – 6 mm",
     "RS PRO"
    ],
    [
     "cage nut",
     "M5 and M6 steel, Essentra",
     "M5 / M6",
     "overall length 12.5 mm; height 9.0 mm (M5) and 9.3 mm (M6)",
     "Essentra (item codes 34002400 and 34002401)"
    ],
    [
     "cage nut",
     "M8 steel, Essentra",
     "M8",
     "overall length 16.3 mm; height 11.6 mm",
     "Essentra (item 34002402)"
    ],
    [
     "cage nut",
     "M5, StarTech CABCAGENUTS",
     "M5",
     "length 0.5 in, width 0.5 in, height 0.4 in (1.3 × 1.3 × 0.9 cm)",
     "StarTech (product dimensions, rounded)"
    ],
    [
     "cage nut",
     "M5 and M6, R-TECH 33-7135 to 33-7138",
     "M5 / M6",
     "eight values as printed, letters A to H not mapped on the sheet read: 13.72, 14.22, 6.1, 9.53, 9.53, 0.8°, and panel 0.7 – 1.6 or 1.7 – 2.5 mm",
     "Rapid Electronics (the 33-7137 panel range prints '0.7.16', read as 0.7 – 1.6)"
    ],
    [
     "cage nut",
     "10-32, 12-24, M6 (CAGNUT series)",
     "10-32 / 12-24 / M6",
     "for 0.375 in (9.54 mm) square holes; M6 sold rear-loading (CAGNUTM6) and front-loading (1421CNBF); no body dimensions on the datasheet",
     "Hammond"
    ],
    [
     "cage nut",
     "M5, PM5CN",
     "M5",
     "snaps into square-hole rack angles; no dimensions on the page",
     "nVent Hoffman"
    ],
    [
     "cage nut",
     "common thread sizes",
     "M5, M6, 10-32, 12-24",
     "10-32 UNF and 12-24 UNC are the inch pair; M5 and M6 are metric",
     "HDBOLT; Hammond"
    ]
   ]
  }
 },
 "sheet_text": "19-inch rack rail holes (EIA-310: 15.875 / 15.875 / 12.7 mm pitch, 465.1 mm spacing, 9.5 mm square) and M5 / M6 / 10-32 / 12-24 cage nuts + 2U square-hole rail gauge — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/rack-cage-nuts-and-rail-holes/  (sheet CC BY 4.0)\nBasis: EIA-310 hole pattern as printed by Digital Loggers, Schneider Electric and Rack Solutions; cage nut sizes from RS PRO, Essentra, StarTech, Rapid Electronics (R-TECH), Hammond, HDBOLT and nVent Hoffman; one 2U rail gauge file\nCatalog version: 2026-10-20\n\nOverall (mm): length 88.9, width 25.0, height 2.0\n- Rail data: the vertical hole pitch repeats 5/8, 5/8, 1/2 in (15.875, 15.875, 12.7 mm) with a U of 44.45 mm starting in the middle of the 1/2 in gap; the hole columns of the two rails are 465.1 mm apart (18 5/16 in); equipment clears 450 mm between rails. These are the figures three makers print as EIA-310 (Schneider cites EIA/ECA-310-E). None of the three pages gives the hole sizes, the rail flange width or the thickness, and the standard itself was not read, so the 9.5 mm square hole comes from the cage nut sheets.\n- Square hole: 9.5 mm (RS PRO's description, HDBOLT 'most common'), 9.53 mm (RS PRO's attribute table) and 0.375 in = 9.54 mm (Hammond). Those are the same 3/8 in rounded; the file uses 9.525 mm. Round-hole and tapped-hole rails (for 10-32, 12-24 and M6 screws) also exist; no source read gives their hole sizes, so they are not on this page.\n- Cage nut body sizes are what each seller prints and they are not a standard: Essentra M5 12.5 × 9.0 mm and M6 12.5 × 9.3 mm (overall length × height), M8 16.3 × 11.6 mm; StarTech M5 about 13 × 13 × 9 mm; RS PRO M6 15 mm overall width; RS PRO prints panel thickness 0.8 – 6 mm, Rapid's R-TECH parts print panel ranges 0.7 – 1.6 and 1.7 – 2.5 mm. Rapid's sheet lists eight dimension values (A to H) without a mapping and they are shown as printed. The cage nuts snap into the square hole from the rail face. Hammond's datasheet calls out 10-32, 12-24 and M6 cage nuts for 0.375 in (9.54 mm) holes and gives torque figures that conflict between versions, so none is shown.\n- File: a 2U strip of rail face, 25 mm wide, 2 mm thick, with six 9.525 mm square holes on the 15.875 / 15.875 / 12.7 mm pitch, U boundaries in the middle of the 12.7 mm gaps. Width and thickness are Xem's choices. It is a hole gauge for a cage nut or square-hole cutout, not a model of a rail. Rack ears and unit heights: rack-19in-ears. Cage nuts have a clip and a captive threaded plate; no model is drawn because the clip geometry is not published as numbers.\n\npart  item  thread  dimension / value  source / note\nrail  rack unit (U) height  —  44.45 mm (1.75 in)  Schneider; Rack Solutions; Digital Loggers (1.75 in)\nrail  vertical hole pitch within a U  —  5/8, 5/8, 1/2 in = 15.875, 15.875, 12.7 mm (Schneider prints 15.9, 15.9, 12.7)  Digital Loggers prints 1/2, 5/8, 5/8 in repeating; Schneider 5/8, 5/8, 1/2\nrail  where a U starts  —  at the middle of the 1/2 in (12.7 mm) gap between holes; a 1U device covers three holes with the notched hole in the middle  Rack Solutions; Schneider\nrail  horizontal hole spacing (between the two rails' hole columns)  —  18 5/16 in = 465.1 mm (18.312 in); Schneider ±1.6 mm  Digital Loggers; Rack Solutions; Schneider\nrail  clearance between rails (minimum) / outside edges of rails (minimum)  —  450 mm (17.72 in) / 483.4 mm  Digital Loggers; Schneider\nrail  equipment front panel width  —  19 in (482.6 mm)  Digital Loggers; Rack Solutions (19 in)\nrail  square hole size  —  9.5 mm (RS description, HDBOLT) / 9.53 mm (RS attribute) / 0.375 in = 9.54 mm (Hammond)  all three are 3/8 in rounded three ways; 9.525 mm is used for the file\nrail  round hole, tapped hole, rail flange width and thickness  —  no published value found in the pages read  —\ncage nut  M6, RS PRO  M6  overall width 15 mm; cutout 9.53 × 9.53 mm; for panel 0.8 – 6 mm  RS PRO\ncage nut  M5 and M6 steel, Essentra  M5 / M6  overall length 12.5 mm; height 9.0 mm (M5) and 9.3 mm (M6)  Essentra (item codes 34002400 and 34002401)\ncage nut  M8 steel, Essentra  M8  overall length 16.3 mm; height 11.6 mm  Essentra (item 34002402)\ncage nut  M5, StarTech CABCAGENUTS  M5  length 0.5 in, width 0.5 in, height 0.4 in (1.3 × 1.3 × 0.9 cm)  StarTech (product dimensions, rounded)\ncage nut  M5 and M6, R-TECH 33-7135 to 33-7138  M5 / M6  eight values as printed, letters A to H not mapped on the sheet read: 13.72, 14.22, 6.1, 9.53, 9.53, 0.8°, and panel 0.7 – 1.6 or 1.7 – 2.5 mm  Rapid Electronics (the 33-7137 panel range prints '0.7.16', read as 0.7 – 1.6)\ncage nut  10-32, 12-24, M6 (CAGNUT series)  10-32 / 12-24 / M6  for 0.375 in (9.54 mm) square holes; M6 sold rear-loading (CAGNUTM6) and front-loading (1421CNBF); no body dimensions on the datasheet  Hammond\ncage nut  M5, PM5CN  M5  snaps into square-hole rack angles; no dimensions on the page  nVent Hoffman\ncage nut  common thread sizes  M5, M6, 10-32, 12-24  10-32 UNF and 12-24 UNC are the inch pair; M5 and M6 are metric  HDBOLT; Hammond\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Digital Loggers: Rack specifications: 1.75 in U, hole spacing 1/2 - 5/8 - 5/8 in, hole columns 18 5/16 in (465.1 mm) apart, minimum opening 17.72 in (450 mm), 19 in front panel — web — Maker page; numbers only. No hole sizes — https://digital-loggers.com/rackspecs.html\n- Schneider Electric (FAQ FA158600): EIA/ECA-310-E as summarised: U = 1.75 in / 44.45 mm; vertical hole spacing 5/8, 5/8, 1/2 in (15.9, 15.9, 12.7 mm); horizontal 18.3 in (465 mm) ±1.6 mm; clearance 450 mm; outside edges 483.4 mm; notched hole marks the U centre — web — Maker FAQ; numbers only. No hole sizes — https://www.se.com/ie/en/faqs/FA158600\n- Rack Solutions: What is EIA-310: U 1.75 in, hole pattern 1/2, 5/8, 5/8 in repeating, the U starts and stops at the middle of the 1/2 in spacing, hole columns 18 5/16 in (465.1 mm), panel width 19 in — web — Maker help page; numbers only. No hole sizes — https://help.racksolutions.com/hc/en-us/articles/10431608060692-What-is-EIA-310\n- RS PRO (RS Components): Cage nut M6: overall width 15 mm, cutout 9.53 × 9.53 mm (description 9.5 × 9.5 mm), panel thickness 0.8 to 6 mm — web — Distributor page; numbers only — https://uk.rs-online.com/web/p/cage-nuts/2662265\n- Essentra Components: Cage nuts M5, M6, M8 (steel, zinc plated): overall length and height — web — Maker catalogue page; numbers only — https://www.essentracomponents.com/en-gb/p/cage-nuts\n- StarTech: Cage nuts M5 (CABCAGENUTS): product length 0.5 in (1.3 cm), width 0.5 in (1.3 cm), height 0.4 in (0.9 cm); square cage nut design for racks with square holes — web — Maker datasheet; numbers only — https://pdf.bomkeyelectronics.com/pdf/31/cabcagenuts_datasheet.pdf\n- Rapid Electronics (R-TECH 33-7135 to 33-7138 sheet): Panel cage nuts M5 and M6, spring steel: eight dimension values A to H per part (letters not mapped on the extracted sheet), panel ranges 0.7 to 1.6 and 1.7 to 2.5 mm — web — Distributor sheet; numbers only — https://static.rapidonline.com/pdf/33-7136_v1.pdf\n- Hammond Manufacturing (via SIC Components datasheet): CAGNUT series: 10-32, 12-24 and M6 cage nuts for 0.375 in (9.54 mm) square-hole punched panel rails; spring steel — web — Maker datasheet; numbers only. No body dimensions — https://datasheet.sic-components.com/cagnut.pdf\n- HDBOLT: Cage nut: thread sizes M5, M6, 10-32 UNF, 12-24 UNC; square hole 9.5 mm (3/8 in) most common — web — Seller page; numbers only — https://hdbolt-final.pages.dev/nuts/cage-nut.html\n- nVent Hoffman: PM5CN cage nut package for square-hole rack angles, M5, mild steel, plated; snaps into the square holes (data sheet linked on the page was not read) — web — Maker product page; no dimensions on the page — https://hoffman.nvent.com/en/hoffman/PM5CN\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/rack-cage-nuts-and-rail-holes/index.json\nAPI: https://xemstudio.com/api/geometry?object=rack-cage-nuts-and-rail-holes\n",
 "sources": [
  {
   "publisher": "Digital Loggers",
   "title": "Rack specifications: 1.75 in U, hole spacing 1/2 - 5/8 - 5/8 in, hole columns 18 5/16 in (465.1 mm) apart, minimum opening 17.72 in (450 mm), 19 in front panel",
   "url": "https://digital-loggers.com/rackspecs.html",
   "formats": [
    "web"
   ],
   "license": "Maker page; numbers only. No hole sizes",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Schneider Electric (FAQ FA158600)",
   "title": "EIA/ECA-310-E as summarised: U = 1.75 in / 44.45 mm; vertical hole spacing 5/8, 5/8, 1/2 in (15.9, 15.9, 12.7 mm); horizontal 18.3 in (465 mm) ±1.6 mm; clearance 450 mm; outside edges 483.4 mm; notched hole marks the U centre",
   "url": "https://www.se.com/ie/en/faqs/FA158600",
   "formats": [
    "web"
   ],
   "license": "Maker FAQ; numbers only. No hole sizes",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Rack Solutions",
   "title": "What is EIA-310: U 1.75 in, hole pattern 1/2, 5/8, 5/8 in repeating, the U starts and stops at the middle of the 1/2 in spacing, hole columns 18 5/16 in (465.1 mm), panel width 19 in",
   "url": "https://help.racksolutions.com/hc/en-us/articles/10431608060692-What-is-EIA-310",
   "formats": [
    "web"
   ],
   "license": "Maker help page; numbers only. No hole sizes",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "RS PRO (RS Components)",
   "title": "Cage nut M6: overall width 15 mm, cutout 9.53 × 9.53 mm (description 9.5 × 9.5 mm), panel thickness 0.8 to 6 mm",
   "url": "https://uk.rs-online.com/web/p/cage-nuts/2662265",
   "formats": [
    "web"
   ],
   "license": "Distributor page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Essentra Components",
   "title": "Cage nuts M5, M6, M8 (steel, zinc plated): overall length and height",
   "url": "https://www.essentracomponents.com/en-gb/p/cage-nuts",
   "formats": [
    "web"
   ],
   "license": "Maker catalogue page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "StarTech",
   "title": "Cage nuts M5 (CABCAGENUTS): product length 0.5 in (1.3 cm), width 0.5 in (1.3 cm), height 0.4 in (0.9 cm); square cage nut design for racks with square holes",
   "url": "https://pdf.bomkeyelectronics.com/pdf/31/cabcagenuts_datasheet.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker datasheet; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Rapid Electronics (R-TECH 33-7135 to 33-7138 sheet)",
   "title": "Panel cage nuts M5 and M6, spring steel: eight dimension values A to H per part (letters not mapped on the extracted sheet), panel ranges 0.7 to 1.6 and 1.7 to 2.5 mm",
   "url": "https://static.rapidonline.com/pdf/33-7136_v1.pdf",
   "formats": [
    "web"
   ],
   "license": "Distributor sheet; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Hammond Manufacturing (via SIC Components datasheet)",
   "title": "CAGNUT series: 10-32, 12-24 and M6 cage nuts for 0.375 in (9.54 mm) square-hole punched panel rails; spring steel",
   "url": "https://datasheet.sic-components.com/cagnut.pdf",
   "formats": [
    "web"
   ],
   "license": "Maker datasheet; numbers only. No body dimensions",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "HDBOLT",
   "title": "Cage nut: thread sizes M5, M6, 10-32 UNF, 12-24 UNC; square hole 9.5 mm (3/8 in) most common",
   "url": "https://hdbolt-final.pages.dev/nuts/cage-nut.html",
   "formats": [
    "web"
   ],
   "license": "Seller page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "nVent Hoffman",
   "title": "PM5CN cage nut package for square-hole rack angles, M5, mild steel, plated; snaps into the square holes (data sheet linked on the page was not read)",
   "url": "https://hoffman.nvent.com/en/hoffman/PM5CN",
   "formats": [
    "web"
   ],
   "license": "Maker product page; no dimensions on the page",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "rack-19in-ears",
  "slide-in-t-nuts",
  "rivet-nuts-flat-head",
  "tee-nuts-for-wood-3-4-prong",
  "machine-screws-metric-pan-cheese-csk"
 ],
 "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": "square hole",
   "exact": "9.525 mm (3/8 in) square; pitch 15.875, 15.875, 12.7 mm per 44.45 mm U",
   "mates": "cage nut cutout 9.53 mm (RS PRO) for panels 0.8 to 6 mm; the nut clips in",
   "fit": "clamp",
   "files": "rack-rail-square-hole-gauge"
  }
 ],
 "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 size is the square hole on a 19-inch rack rail?",
   "a": "About 9.5 mm (3/8 in): 9.5 mm, 9.53 mm and 0.375 in (9.54 mm) are printed by RS PRO, HDBOLT and Hammond. The pitch is 15.875, 15.875, 12.7 mm, 44.45 mm per U."
  },
  {
   "q": "What cage nut thread sizes are common for racks?",
   "a": "M5, M6, 10-32 and 12-24 (HDBOLT, Hammond, Essentra, StarTech)."
  },
  {
   "q": "How far apart are the two rails' hole columns?",
   "a": "465.1 mm (18 5/16 in) centre to centre (Digital Loggers, Rack Solutions); Schneider prints 465 mm ±1.6."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "rack-rail-square-hole-gauge-2u",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/rack-cage-nuts-and-rail-holes/rack-rail-square-hole-gauge-2u.step",
   "stl": "https://xemstudio.com/files/hardware/rack-cage-nuts-and-rail-holes/rack-rail-square-hole-gauge-2u.stl",
   "note": "2U rack rail strip, 25 wide × 88.9 long (2 × 44.45) × 2 mm thick, six 9.525 mm square holes (3/8 in) at 6.35, 22.225, 38.1, 50.8, 66.675 and 82.55 mm from one end (pitch 15.875, 15.875, 12.7 mm per U, U boundaries in the middle of the 12.7 mm gaps); width and thickness are Xem's choices; one rail only, no mounting-flange return, no round or tapped hole"
  }
 ],
 "markdown": "https://xemstudio.com/objects/rack-cage-nuts-and-rail-holes/index.md"
}