{
 "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": "child-car-seat-harness-buckle",
 "name": "Child car seat harness buckle (reference only)",
 "kind": "modern",
 "category": "Everyday mounts",
 "group": "Strollers & car seats",
 "year": null,
 "question": "What are the dimensions of a car seat harness buckle?",
 "tags": [
  "car seat",
  "buckle",
  "harness",
  "child restraint",
  "safety"
 ],
 "aliases": [
  "car seat buckle dimensions",
  "car seat buckle size",
  "car seat chest clip size",
  "car seat harness buckle"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "planned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/child-car-seat-harness-buckle/",
 "sheet_txt": "https://xemstudio.com/objects/child-car-seat-harness-buckle/sheet.txt",
 "sheet": {
  "basis": "No car-seat maker publishes buckle, tongue or chest-clip dimensions. This page records that, the safety guidance, and the planned reference scan of the exterior envelope only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Safety: a child car seat's harness, buckle, tongues and chest clip are crash-tested as part of the seat. NHTSA advises that aftermarket products are not recommended for use with car seats unless made or allowed by the car seat's maker, and Transport Canada reports that child-restraint makers advise that no third-party aftermarket products be used with their seats. Geometry here is for reference and for accessories that do not touch the restraint system. It is not for replacement or modified buckles, harness or chest-clip parts, and nothing should attach to or change the harness or buckle.",
   "Popular seats people ask about: Doona, Nuna PIPA series, and the convertible seats from Graco, Chicco and Britax. Their buckle and chest-clip dimensions are not published.",
   "What is planned: a reference scan of the outside envelope of a few popular seats' buckle housings, so that things designed around the seat (stroller and car accessories) can stay clear of it.",
   "What will never be here: buckle, tongue or chest-clip geometry, or any adapter, clip, cover or part that fits on, attaches to or changes the harness, buckle or chest clip."
  ],
  "table": {
   "columns": [
    "feature",
    "published value",
    "from"
   ],
   "rows": [
    [
     "buckle, tongue, chest clip dimensions",
     "not published",
     "—"
    ],
    [
     "geometry on this page",
     "none (reference scan of the outside envelope planned)",
     "—"
    ]
   ]
  }
 },
 "sheet_text": "Child car seat harness buckle (reference only) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/child-car-seat-harness-buckle/  (CC BY 4.0)\nBasis: No car-seat maker publishes buckle, tongue or chest-clip dimensions. This page records that, the safety guidance, and the planned reference scan of the exterior envelope only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Safety: a child car seat's harness, buckle, tongues and chest clip are crash-tested as part of the seat. NHTSA advises that aftermarket products are not recommended for use with car seats unless made or allowed by the car seat's maker, and Transport Canada reports that child-restraint makers advise that no third-party aftermarket products be used with their seats. Geometry here is for reference and for accessories that do not touch the restraint system. It is not for replacement or modified buckles, harness or chest-clip parts, and nothing should attach to or change the harness or buckle.\n- Popular seats people ask about: Doona, Nuna PIPA series, and the convertible seats from Graco, Chicco and Britax. Their buckle and chest-clip dimensions are not published.\n- What is planned: a reference scan of the outside envelope of a few popular seats' buckle housings, so that things designed around the seat (stroller and car accessories) can stay clear of it.\n- What will never be here: buckle, tongue or chest-clip geometry, or any adapter, clip, cover or part that fits on, attaches to or changes the harness, buckle or chest clip.\n\nfeature  published value  from\nbuckle, tongue, chest clip dimensions  not published  —\ngeometry on this page  none (reference scan of the outside envelope planned)  —\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- NHTSA: Car seat glossary: aftermarket products are not recommended for use with car seats unless made or allowed by the car seat manufacturer — web — US government work [verify license at link] — https://www.nhtsa.gov/car-seats-and-booster-seats/car-seat-glossary\n- Transport Canada: Third-party aftermarket products for children's restraint systems — web — Government of Canada [verify license at link] — https://tc.canada.ca/en/road-transportation/defects-recalls-vehicles-tires-child-car-seats/third-party-aftermarket-products-children-s-restraint-systems\n- Car Seats for the Littles: Non-approved products for car seats — web — reference [verify license at link] — https://csftl.org/aftermarket-products/\n\nXem Studio scan: planned. Mesh $6, STEP $12, target tolerance ±0.15 mm.\nAPI: https://xemstudio.com/api/geometry?object=child-car-seat-harness-buckle\n",
 "sources": [
  {
   "publisher": "NHTSA",
   "title": "Car seat glossary: aftermarket products are not recommended for use with car seats unless made or allowed by the car seat manufacturer",
   "url": "https://www.nhtsa.gov/car-seats-and-booster-seats/car-seat-glossary",
   "formats": [
    "web"
   ],
   "license": "US government work",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Transport Canada",
   "title": "Third-party aftermarket products for children's restraint systems",
   "url": "https://tc.canada.ca/en/road-transportation/defects-recalls-vehicles-tires-child-car-seats/third-party-aftermarket-products-children-s-restraint-systems",
   "formats": [
    "web"
   ],
   "license": "Government of Canada",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Car Seats for the Littles",
   "title": "Non-approved products for car seats",
   "url": "https://csftl.org/aftermarket-products/",
   "formats": [
    "web"
   ],
   "license": "reference",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "planned",
  "sheet_free": true,
  "mesh_price_usd": 6,
  "step_price_usd": 12,
  "tolerance_mm": 0.15
 },
 "related": [
  "doona-car-seat-stroller",
  "nuna-pipa-rx"
 ],
 "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": "Can I make a replacement buckle, chest clip or harness part from this?",
   "a": "No. The harness, buckle and chest clip are tested with the seat; NHTSA advises against aftermarket products on car seats, and Transport Canada reports that seat makers do too. Replacement restraint parts come only from the seat's maker. This page is reference geometry for things that do not touch the restraint system."
  },
  {
   "q": "What are the dimensions of a car seat buckle?",
   "a": "Not published by the seat makers. A reference scan of the outside envelope is planned, for keeping things around the seat clear of it."
  },
  {
   "q": "Can I add a cover, clip or holder to the buckle or harness?",
   "a": "No. NHTSA advises against aftermarket products on car seats unless the seat's maker made or allows them; nothing should attach to or change the harness or buckle."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "mesh",
   "status": "planned",
   "price_usd": 6,
   "target_tolerance_mm": 0.15
  },
  {
   "file": "step",
   "status": "planned",
   "price_usd": 12,
   "target_tolerance_mm": 0.15
  }
 ],
 "markdown": "https://xemstudio.com/objects/child-car-seat-harness-buckle/index.md"
}