{
 "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": "4040-aluminum-extrusion-20-series",
 "name": "4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2)",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Framing",
 "year": null,
 "question": "What are the exact dimensions of 4040 aluminum extrusion?",
 "tags": [
  "extrusion",
  "t-slot",
  "aluminum extrusion",
  "frame",
  "4040",
  "20-series"
 ],
 "aliases": [
  "4040 extrusion step",
  "4040 extrusion dxf",
  "4040 extrusion dimensions",
  "4040 aluminum extrusion cad",
  "40x40 extrusion profile",
  "4040 t slot profile",
  "4040 profile 6 mm slot",
  "4040 b-type extrusion"
 ],
 "overall_mm": {
  "length": null,
  "width": 40,
  "height": 40
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 2,
 "url": "https://xemstudio.com/objects/4040-aluminum-extrusion-20-series/",
 "sheet_txt": "https://xemstudio.com/objects/4040-aluminum-extrusion-20-series/sheet.txt",
 "sheet": {
  "basis": "Misumi 5 series, 6 mm slot, from Misumi's dimensioned drawing of this profile; every slot, lip, cavity, bore and outline number is the drawing's",
  "overall_mm": {
   "length": null,
   "width": 40,
   "height": 40
  },
  "notes": [
   "4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2): 40 × 40 mm, 8 slots on a 20 mm pitch (Misumi 5 series, 6 mm slot). Source: Misumi's dimensioned drawing of this profile. Files: STEP and STL at 100, 1000 mm with square ends, and a DXF of the exact cross-section (mm), the master to extrude to any length. The section is centred on the origin and extruded along +Z from z = 0.",
   "Slot: opening 6 mm, lip 2 mm thick at the opening, cavity 12 mm wide under the lips, 6 mm from the face to the cavity floor. Centre bore Ø4.2 mm per cell (the M5 tap drill).",
   "Cavity side walls: the cavity is 12 mm wide under the lips, then follows the diagonal webs (1.5 mm thick, stated) down to the floor; the webs lie on the cell diagonals (45°), as drawn. The web thickness is stated on this series' 2060, 2080 and 4040 drawings.",
   "The closed hollows between cells are drawn from the stated web (1.5 mm), core (8 mm square round each bore) and 2 mm face wall.",
   "Outer corners R1 (stated).",
   "Wrapping it: to make a part that fits around the bar, subtract the 1000 mm file (or extrude the DXF) from your solid; the outline is the drawing's 40 × 40 mm with no allowance, so open the pocket by your process's socket fit (see Mating features).",
   "Attachments: the 20-series (6 mm slot) T-nuts, end caps, feet, brackets, gussets, plates and slot covers are cut from these same numbers; the fit check (tools/asm_extrusion_fit.py) placed each one on this profile with zero overlap."
  ],
  "table": {
   "columns": [
    "feature",
    "size",
    "from"
   ],
   "rows": [
    [
     "outline",
     "40 × 40 mm, R1 corners",
     "drawing"
    ],
    [
     "slot pitch",
     "20 mm",
     "drawing"
    ],
    [
     "slot opening",
     "6 mm",
     "drawing"
    ],
    [
     "lip thickness at the opening",
     "2 mm",
     "drawing"
    ],
    [
     "cavity width under the lips",
     "12 mm",
     "drawing"
    ],
    [
     "face to cavity floor",
     "6 mm",
     "drawing"
    ],
    [
     "cavity depth under the lip (at the cavity wall)",
     "4 mm",
     "drawing"
    ],
    [
     "core between opposite floors",
     "8 mm",
     "pitch − 2 × face-to-floor"
    ],
    [
     "diagonal web",
     "1.5 mm",
     "drawing"
    ],
    [
     "centre bore",
     "Ø4.2 mm × 4",
     "drawing"
    ],
    [
     "cross-section area",
     "472 mm²",
     "maker's page"
    ],
    [
     "mass",
     "1.28 kg/m",
     "maker's page"
    ],
    [
     "Ix / Iy",
     "8.89 × 10⁴ / 8.89 × 10⁴ mm⁴",
     "maker's page"
    ],
    [
     "area of this model's section",
     "521.1 mm²",
     "computed from the DXF"
    ]
   ]
  }
 },
 "sheet_text": "4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/4040-aluminum-extrusion-20-series/  (CC BY 4.0)\nBasis: Misumi 5 series, 6 mm slot, from Misumi's dimensioned drawing of this profile; every slot, lip, cavity, bore and outline number is the drawing's\nCatalog version: 2026-10-20\n\nOverall (mm): width 40.0, height 40.0\n- 4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2): 40 × 40 mm, 8 slots on a 20 mm pitch (Misumi 5 series, 6 mm slot). Source: Misumi's dimensioned drawing of this profile. Files: STEP and STL at 100, 1000 mm with square ends, and a DXF of the exact cross-section (mm), the master to extrude to any length. The section is centred on the origin and extruded along +Z from z = 0.\n- Slot: opening 6 mm, lip 2 mm thick at the opening, cavity 12 mm wide under the lips, 6 mm from the face to the cavity floor. Centre bore Ø4.2 mm per cell (the M5 tap drill).\n- Cavity side walls: the cavity is 12 mm wide under the lips, then follows the diagonal webs (1.5 mm thick, stated) down to the floor; the webs lie on the cell diagonals (45°), as drawn. The web thickness is stated on this series' 2060, 2080 and 4040 drawings.\n- The closed hollows between cells are drawn from the stated web (1.5 mm), core (8 mm square round each bore) and 2 mm face wall.\n- Outer corners R1 (stated).\n- Wrapping it: to make a part that fits around the bar, subtract the 1000 mm file (or extrude the DXF) from your solid; the outline is the drawing's 40 × 40 mm with no allowance, so open the pocket by your process's socket fit (see Mating features).\n- Attachments: the 20-series (6 mm slot) T-nuts, end caps, feet, brackets, gussets, plates and slot covers are cut from these same numbers; the fit check (tools/asm_extrusion_fit.py) placed each one on this profile with zero overlap.\n\nfeature  size  from\noutline  40 × 40 mm, R1 corners  drawing\nslot pitch  20 mm  drawing\nslot opening  6 mm  drawing\nlip thickness at the opening  2 mm  drawing\ncavity width under the lips  12 mm  drawing\nface to cavity floor  6 mm  drawing\ncavity depth under the lip (at the cavity wall)  4 mm  drawing\ncore between opposite floors  8 mm  pitch − 2 × face-to-floor\ndiagonal web  1.5 mm  drawing\ncentre bore  Ø4.2 mm × 4  drawing\ncross-section area  472 mm²  maker's page\nmass  1.28 kg/m  maker's page\nIx / Iy  8.89 × 10⁴ / 8.89 × 10⁴ mm⁴  maker's page\narea of this model's section  521.1 mm²  computed from the DXF\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Misumi: 40x40 Aluminum Extrusion - 5 Series, Base 20: product page with the cross-section drawing and section properties — web — Misumi site terms [verify license at link] — https://us.misumi-ec.com/vona2/detail/110302684530/\n- Misumi: 4040 dimensioned cross-section drawing — image — Misumi site terms [verify license at link] — https://us.misumi-ec.com/linked/item/10302684530/img/Picture7_new.jpg\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 2 parts): https://xemstudio.com/files/hardware/4040-aluminum-extrusion-20-series/index.json\nAPI: https://xemstudio.com/api/geometry?object=4040-aluminum-extrusion-20-series\n",
 "sources": [
  {
   "publisher": "Misumi",
   "title": "40x40 Aluminum Extrusion - 5 Series, Base 20: product page with the cross-section drawing and section properties",
   "url": "https://us.misumi-ec.com/vona2/detail/110302684530/",
   "formats": [
    "web"
   ],
   "license": "Misumi site terms",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Misumi",
   "title": "4040 dimensioned cross-section drawing",
   "url": "https://us.misumi-ec.com/linked/item/10302684530/img/Picture7_new.jpg",
   "formats": [
    "image"
   ],
   "license": "Misumi site terms",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "2020-aluminum-extrusion",
  "2040-aluminum-extrusion",
  "2060-aluminum-extrusion",
  "2080-aluminum-extrusion",
  "slide-in-t-nuts",
  "drop-in-t-nuts",
  "t-slot-end-caps",
  "t-slot-corner-brackets",
  "button-head-screws-metric"
 ],
 "fits": [
  {
   "role": "Parts that fit it",
   "items": [
    {
     "slug": "slide-in-t-nuts",
     "why": "tongue in the opening, body in the cavity (slide)"
    },
    {
     "slug": "drop-in-t-nuts",
     "why": "drops through the opening, turns 90° in the cavity"
    },
    {
     "slug": "t-slot-corner-brackets",
     "why": "legs flat on two profile faces at 90°"
    },
    {
     "slug": "t-slot-gussets",
     "why": "legs on two profile faces in the inside corner"
    },
    {
     "slug": "t-slot-covers",
     "why": "stem in the slot opening, barb behind the lips"
    },
    {
     "slug": "t-slot-joining-plates",
     "why": "holes over the slot centrelines on the profile pitch"
    },
    {
     "slug": "t-slot-end-caps",
     "why": "end-cap-20-2x2: pins in the centre bores (press)"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "2020-aluminum-extrusion",
     "why": "same 20-series (6 mm slot) slot, 20 × 20 mm"
    },
    {
     "slug": "2040-aluminum-extrusion",
     "why": "same 20-series (6 mm slot) slot, 20 × 40 mm"
    },
    {
     "slug": "2060-aluminum-extrusion",
     "why": "same 20-series (6 mm slot) slot, 20 × 60 mm"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "button-head-screws-metric",
     "why": "M5 screws through brackets into the T-nuts"
    }
   ]
  }
 ],
 "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": [
  {
   "feature": "slot opening",
   "exact": "6",
   "mates": "T-nut tongue, slot-cover stem (20-series (6 mm slot))",
   "fit": "slide",
   "files": "all"
  },
  {
   "feature": "slot cavity",
   "exact": "12 wide under the lips, face to floor 6, lip 2",
   "mates": "T-nut body (slide-in, drop-in)",
   "fit": "slide",
   "files": "all"
  },
  {
   "feature": "centre bore",
   "exact": "Ø4.2",
   "mates": "M5 thread (tap drill 4.2); end-cap pin",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "outline",
   "exact": "40 × 40, R1",
   "mates": "end-cap outline, foot socket, a pocket that wraps the bar",
   "fit": "socket",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "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. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "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 is the slot size of 4040 extrusion?",
   "a": "Opening 6 mm, lip 2 mm, cavity 12 mm wide under the lips and 6 mm deep from the face to the floor, per Misumi 5 series, 6 mm slot's drawing."
  },
  {
   "q": "What T-nuts fit 4040 extrusion?",
   "a": "The 20-series (6 mm slot) nuts: slide-in (tnut-slide-20-m3, tnut-slide-20-m4, tnut-slide-20-m5) and drop-in versions, threaded M3, M4, M5 as tap-drill holes, cut to this slot's exact space."
  },
  {
   "q": "Can I subtract this file to make a part that fits the extrusion exactly?",
   "a": "Yes: the outline is exactly 40 × 40 mm with R1 corners; extrude the DXF or subtract the 1000 mm STEP, then open the pocket by your fit."
  },
  {
   "q": "How heavy is 4040 extrusion?",
   "a": "1.28 kg/m, 472 mm² section, as Misumi states. This model's section is larger because closed hollows / cavity details the drawing leaves undimensioned are drawn filled; use the stated weight, not the model's volume."
  },
  {
   "q": "What in this model is not taken straight from the drawing?",
   "a": "The closed hollows between cells are drawn from the stated web (1.5 mm), core (8 mm square round each bore) and 2 mm face wall."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "4040-20s-100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/4040-aluminum-extrusion-20-series/4040-20s-100.step",
   "stl": "https://xemstudio.com/files/hardware/4040-aluminum-extrusion-20-series/4040-20s-100.stl",
   "note": "4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2): 40 × 40 mm section, 100 mm long, square ends; DXF = the exact cross-section in mm"
  },
  {
   "file": "4040-20s-1000",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/4040-aluminum-extrusion-20-series/4040-20s-1000.step",
   "stl": "https://xemstudio.com/files/hardware/4040-aluminum-extrusion-20-series/4040-20s-1000.stl",
   "note": "4040 aluminum extrusion, 6 mm slot (20-series, 2 × 2): 40 × 40 mm section, 1000 mm long, square ends; DXF = the exact cross-section in mm"
  }
 ],
 "markdown": "https://xemstudio.com/objects/4040-aluminum-extrusion-20-series/index.md"
}