{
 "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": "adafruit-sgp40-4829",
 "name": "Adafruit SGP40 air quality sensor (#4829, STEMMA QT): 25.4 × 17.78 mm board and 4 mounting holes",
 "kind": "modern",
 "category": "Electronic components",
 "group": "Modules, sensors & displays",
 "year": null,
 "question": "What are the Adafruit SGP40 (product 4829) breakout dimensions and mounting-hole positions?",
 "tags": [
  "sgp40",
  "adafruit sgp40 dimensions",
  "sgp40 breakout mounting holes",
  "voc sensor breakout",
  "air quality sensor mount",
  "stemma qt breakout"
 ],
 "aliases": [
  "Adafruit SGP40",
  "Adafruit 4829",
  "SGP40 breakout",
  "SGP40 Air Quality Sensor Breakout",
  "Sensirion SGP40 VOC index breakout",
  "SGP40 STEMMA QT"
 ],
 "overall_mm": {
  "length": 25.4,
  "width": 17.78,
  "height": 4.55
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/adafruit-sgp40-4829/",
 "sheet_txt": "https://xemstudio.com/objects/adafruit-sgp40-4829/sheet.txt",
 "sheet": {
  "basis": "Adafruit's EagleCAD board file for the SGP40 STEMMA QT breakout, with connector height from the JST SH datasheet.",
  "overall_mm": {
   "length": 25.4,
   "width": 17.78,
   "height": 4.55
  },
  "notes": [
   "Board 25.40 × 17.78 with R2.54 corners, centred, board bottom at 0. Board thickness 1.6 is assumed (Adafruit's board file does not state it); everything else is from the board file.",
   "Four plated Ø2.5 mounting holes at (±10.16, ±6.35) from the board centre: a 20.32 × 12.70 rectangle.",
   "Two STEMMA QT (JST SH 4-pin) connectors on the short edges, openings facing outward; 4.55 overall height.",
   "Not modelled: the loose 1×5 0.1 in header along one long edge and the 2.44 × 2.44 SGP40 sensor; leave the sensor open to air.",
   "All dimensions are exact nominal millimetres, true size, with no tolerance added."
  ],
  "table": {
   "columns": [
    "hole",
    "x (mm)",
    "y (mm)",
    "diameter (mm)"
   ],
   "rows": [
    [
     "1",
     "-10.16",
     "-6.35",
     "2.5"
    ],
    [
     "2",
     "+10.16",
     "-6.35",
     "2.5"
    ],
    [
     "3",
     "-10.16",
     "+6.35",
     "2.5"
    ],
    [
     "4",
     "+10.16",
     "+6.35",
     "2.5"
    ]
   ]
  }
 },
 "sheet_text": "Adafruit SGP40 air quality sensor (#4829, STEMMA QT): 25.4 × 17.78 mm board and 4 mounting holes — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/adafruit-sgp40-4829/  (sheet CC BY 4.0)\nBasis: Adafruit's EagleCAD board file for the SGP40 STEMMA QT breakout, with connector height from the JST SH datasheet.\nCatalog version: 2026-10-20\n\nOverall (mm): length 25.4, width 17.78, height 4.55\n- Board 25.40 × 17.78 with R2.54 corners, centred, board bottom at 0. Board thickness 1.6 is assumed (Adafruit's board file does not state it); everything else is from the board file.\n- Four plated Ø2.5 mounting holes at (±10.16, ±6.35) from the board centre: a 20.32 × 12.70 rectangle.\n- Two STEMMA QT (JST SH 4-pin) connectors on the short edges, openings facing outward; 4.55 overall height.\n- Not modelled: the loose 1×5 0.1 in header along one long edge and the 2.44 × 2.44 SGP40 sensor; leave the sensor open to air.\n- All dimensions are exact nominal millimetres, true size, with no tolerance added.\n\nhole  x (mm)  y (mm)  diameter (mm)\n1  -10.16  -6.35  2.5\n2  +10.16  -6.35  2.5\n3  -10.16  +6.35  2.5\n4  +10.16  +6.35  2.5\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Adafruit: Adafruit SGP40 Air Quality Sensor Breakout - STEMMA QT (#4829) — web — Publisher's page; dimensions are facts — https://www.adafruit.com/product/4829\n- Adafruit: Adafruit-SGP40-PCB repository — web — Publisher's page; dimensions are facts — https://github.com/adafruit/Adafruit-SGP40-PCB\n- Adafruit Learning System: Adafruit SGP40 Air Quality Sensor guide — web — Publisher's page; dimensions are facts — https://learn.adafruit.com/adafruit-sgp40\n- JST: SH connector series datasheet — web — Publisher's page; dimensions are facts — https://www.jst-mfg.com/product/pdf/eng/eSH.pdf\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/adafruit-sgp40-4829/index.json\nAPI: https://xemstudio.com/api/geometry?object=adafruit-sgp40-4829\n",
 "sources": [
  {
   "publisher": "Adafruit",
   "title": "Adafruit SGP40 Air Quality Sensor Breakout - STEMMA QT (#4829)",
   "url": "https://www.adafruit.com/product/4829",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
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  {
   "publisher": "Adafruit",
   "title": "Adafruit-SGP40-PCB repository",
   "url": "https://github.com/adafruit/Adafruit-SGP40-PCB",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
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  {
   "publisher": "Adafruit Learning System",
   "title": "Adafruit SGP40 Air Quality Sensor guide",
   "url": "https://learn.adafruit.com/adafruit-sgp40",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "JST",
   "title": "SH connector series datasheet",
   "url": "https://www.jst-mfg.com/product/pdf/eng/eSH.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
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  "tolerance_mm": null
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 "related": [
  "adafruit-stemma-qt-breakouts",
  "jst-sh-connector",
  "threaded-standoffs-metric",
  "pin-headers-2.54mm",
  "adafruit-vl53l0x-3317",
  "adafruit-bme280-breakout-original"
 ],
 "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": "Mounting holes",
   "exact": "4 × Ø2.5 on 20.32 × 12.70",
   "mates": "M2.5 or #2-56 screws and standoffs",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "STEMMA QT connectors",
   "exact": "2 × JST SH 4-pin, 4.25 × 6.10, top 4.55, openings on both short edges",
   "mates": "JST SH 4-pin cable plug; leave cable clearance past each short edge",
   "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": "How big is the Adafruit SGP40 breakout?",
   "a": "25.40 × 17.78 mm, 1.6 mm board (assumed), 4.55 mm tall over the STEMMA QT connectors."
  },
  {
   "q": "Where are its mounting holes?",
   "a": "Four Ø2.5 holes on a 20.32 × 12.70 mm rectangle centred on the board."
  }
 ],
 "files_license": null,
 "offers": [
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   "file": "adafruit-sgp40-4829",
   "formats": [
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   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/adafruit-sgp40-4829/adafruit-sgp40-4829.step",
   "stl": "https://xemstudio.com/files/hardware/adafruit-sgp40-4829/adafruit-sgp40-4829.stl",
   "note": "Adafruit SGP40 air quality sensor (#4829, STEMMA QT): 25.4 × 17.78 mm board and 4 mounting holes"
  }
 ],
 "markdown": "https://xemstudio.com/objects/adafruit-sgp40-4829/index.md"
}