{
 "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": "2x4-cross-block-connector",
 "name": "3D printable 2x4 cross connector: joins two 2x4s on edge crossing like a plus, one stacked on the other (STL, STEP)",
 "kind": "hardware",
 "category": "Joinery",
 "group": "3D-print connectors",
 "year": null,
 "question": "Is there a 3D printable block that holds two 2x4s crossing at 90 degrees, both on edge, without cutting the wood?",
 "tags": [
  "2x4 connector",
  "2x4 cross connector",
  "3d printed 2x4 bracket",
  "lumber connector",
  "2x4 joint",
  "cross joint",
  "plus joint",
  "stacked lumber",
  "stl",
  "fdm"
 ],
 "aliases": [
  "3d printed 2x4 connector stl",
  "2x4 cross bracket",
  "printable lumber connector",
  "2x4 plus connector",
  "2x4 stacking block",
  "perpendicular 2x4 connector",
  "2x4 on edge connector",
  "cross lap block 2x4"
 ],
 "overall_mm": {
  "length": 55.5,
  "width": 55.5,
  "height": 90
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/2x4-cross-block-connector/",
 "sheet_txt": "https://xemstudio.com/objects/2x4-cross-block-connector/sheet.txt",
 "sheet": {
  "basis": "2x4 dressed (dry) size 1-1/2 × 3-1/2 in (38.1 × 88.9 mm) per DOC PS 20 American Softwood Lumber Standard; 1.4 mm sliding clearance is Xem's FDM default for this part.",
  "overall_mm": {
   "length": 55.5,
   "width": 55.5,
   "height": 90
  },
  "notes": [
   "Both boards stand on edge (the 1-1/2 in side is the width). The block slides down over the lower board and the upper board drops into the top slot at 90°, so the stack is about 7 in to the top of the upper board.",
   "No cutting or notching of the lumber. Add a screw through a wall into each board if the joint must not lift apart.",
   "Slots are 39.5 mm for a 38.1 mm board. Rough-sawn, wet or swollen 2x4s can run thicker: test-fit one block first.",
   "Print upright as modelled, 4 or more walls, 20 % or more infill, PETG or ABS outdoors. No supports: the lower slot's 39.5 mm ceiling bridges."
  ],
  "table": {
   "columns": [
    "feature",
    "size mm",
    "fits"
   ],
   "rows": [
    [
     "block",
     "55.5 × 55.5 × 90",
     "—"
    ],
    [
     "lower slot (opens down, along X)",
     "39.5 wide × 40 deep",
     "2x4 on edge, 38.1 thick"
    ],
    [
     "upper slot (opens up, along Y)",
     "39.5 wide × 40 deep",
     "2x4 on edge, 38.1 thick"
    ],
    [
     "walls / web",
     "8 / 10",
     "—"
    ],
    [
     "lead-in chamfer",
     "1.5",
     "—"
    ]
   ]
  }
 },
 "sheet_text": "3D printable 2x4 cross connector: joins two 2x4s on edge crossing like a plus, one stacked on the other (STL, STEP) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/2x4-cross-block-connector/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: 2x4 dressed (dry) size 1-1/2 × 3-1/2 in (38.1 × 88.9 mm) per DOC PS 20 American Softwood Lumber Standard; 1.4 mm sliding clearance is Xem's FDM default for this part.\nCatalog version: 2026-10-20\n\nOverall (mm): length 55.5, width 55.5, height 90.0\n- Both boards stand on edge (the 1-1/2 in side is the width). The block slides down over the lower board and the upper board drops into the top slot at 90°, so the stack is about 7 in to the top of the upper board.\n- No cutting or notching of the lumber. Add a screw through a wall into each board if the joint must not lift apart.\n- Slots are 39.5 mm for a 38.1 mm board. Rough-sawn, wet or swollen 2x4s can run thicker: test-fit one block first.\n- Print upright as modelled, 4 or more walls, 20 % or more infill, PETG or ABS outdoors. No supports: the lower slot's 39.5 mm ceiling bridges.\n\nfeature  size mm  fits\nblock  55.5 × 55.5 × 90  —\nlower slot (opens down, along X)  39.5 wide × 40 deep  2x4 on edge, 38.1 thick\nupper slot (opens up, along Y)  39.5 wide × 40 deep  2x4 on edge, 38.1 thick\nwalls / web  8 / 10  —\nlead-in chamfer  1.5  —\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- NIST / ALSC: Voluntary Product Standard PS 20-25, American Softwood Lumber Standard — web — Publisher's page; dimensions are facts — https://www.nist.gov/document/ps-20-25-final\n- American Wood Council: Weights and Measurement: nominal vs actual lumber sizes — web — Publisher's page; dimensions are facts — https://awc.org/weights-and-measurement\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/2x4-cross-block-connector/index.json\nAPI: https://xemstudio.com/api/geometry?object=2x4-cross-block-connector\n",
 "sources": [
  {
   "publisher": "NIST / ALSC",
   "title": "Voluntary Product Standard PS 20-25, American Softwood Lumber Standard",
   "url": "https://www.nist.gov/document/ps-20-25-final",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "American Wood Council",
   "title": "Weights and Measurement: nominal vs actual lumber sizes",
   "url": "https://awc.org/weights-and-measurement",
   "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": [
  "dimensional-lumber",
  "cross-lap-joint",
  "half-lap-joint"
 ],
 "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": "lower slot",
   "exact": "39.5 mm wide, 40 mm deep",
   "mates": "2x4 on edge (38.1 mm)",
   "fit": "slide",
   "files": "all"
  },
  {
   "feature": "upper slot",
   "exact": "39.5 mm wide, 40 mm deep",
   "mates": "2x4 on edge (38.1 mm)",
   "fit": "slide",
   "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 size is a 2x4 really?",
   "a": "1-1/2 × 3-1/2 in (38.1 × 88.9 mm) dry and dressed. The slots here are 39.5 mm so the 38.1 mm side slides in."
  },
  {
   "q": "Do the boards need to be cut or notched?",
   "a": "No. The block slides over one board and the other drops into the top slot; the wood stays full length."
  },
  {
   "q": "Does it work with the boards lying flat?",
   "a": "No. Both slots fit the 1-1/2 in side, so both boards stand on edge."
  },
  {
   "q": "How do I print it without supports?",
   "a": "Print it upright as modelled. The lower slot's 39.5 mm ceiling bridges on any tuned FDM printer."
  },
  {
   "q": "Will it hold if I lift the top board?",
   "a": "It locates the boards but does not lock them. Drive a screw through a wall into each board if it must not come apart."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "2x4-cross-block",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/2x4-cross-block-connector/2x4-cross-block.step",
   "stl": "https://xemstudio.com/files/hardware/2x4-cross-block-connector/2x4-cross-block.stl",
   "note": "2x4 cross connector: 55.5 × 55.5 × 90 mm block, two 39.5 mm slots 40 mm deep at 90°, one down, one up; prints upright with no supports"
  }
 ],
 "markdown": "https://xemstudio.com/objects/2x4-cross-block-connector/index.md"
}