{
 "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": "sbr-supported-rail-linear-guides-sbr12-sbr30",
 "name": "SBR supported linear rails SBR12 to SBR30 and SBR..UU blocks: shaft, base width, hole spacing, hole size, block holes (sources shown where they disagree)",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the dimensions of SBR12, SBR16, SBR20, SBR25 and SBR30 supported linear rails and SBR..UU blocks: base width, hole spacing, hole diameter, block holes and thread?",
 "tags": [
  "sbr",
  "supported rail",
  "linear guide",
  "sbr16",
  "sbr20",
  "round rail",
  "linear rail",
  "block",
  "standard"
 ],
 "aliases": [
  "sbr16 dimensions",
  "sbr20 dimensions",
  "sbr12 rail",
  "sbr25 rail",
  "sbr30",
  "sbr16uu block",
  "sbr20uu mounting holes",
  "sbr rail hole spacing",
  "supported linear rail 20mm dimensions",
  "sbr20 base width 45",
  "sbr16 rail 40 mm wide",
  "sbr linear rail bolt size",
  "sbr rail hole diameter"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/sbr-supported-rail-linear-guides-sbr12-sbr30/",
 "sheet_txt": "https://xemstudio.com/objects/sbr-supported-rail-linear-guides-sbr12-sbr30/sheet.txt",
 "sheet": {
  "basis": "WF International, the VEVOR SBR manual and BuildYourCNC (SBR20 only); only values with a clear meaning are shown and the disagreements are listed",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "SBR rails are a shaft of the stated diameter (a hardened, ground round rail) clamped along its length by an aluminium support with a slot, bolted down through holes in the base; SBR..UU is the matching open linear ball bushing block. The family is a de-facto catalog standard (the same sizes appear as SBR, SBS, TBR and TBS from different makers), not an ISO / DIN standard; makers' tables use their own column letters.",
   "What is shown and why: three sources were read and the page keeps only values with a clear meaning. WF International (Taiwan, labelled table), the VEVOR product manual (the same numbers in a table whose letters are not defined) and BuildYourCNC for SBR20 alone (labelled: base width 45, hole spacing 30.226 across, 150 along). They agree on the shaft sizes and on the base width of the rail support (WF 'W2' = VEVOR 'B' = 32 / 40 / 45 / 55 for SBR12 / 16 / 20 / 25), its thickness (4 / 5 / 5 / 6) and the blocks' W, L, B, C and thread for SBR16UU, SBR20UU and SBR25UU. They disagree on the hole spacing across the rail for SBR12 (23 vs 22), SBR20 (30 vs 35) and SBR25 (35 vs 40), on the hole diameter (Ø4.5 vs Ø5, Ø5.5 vs Ø6 for SBR12 / 16 / 20), and on every SBR12UU number (W 36 vs 40, L 34 vs 39, B 26 vs 28, C 24 vs 26). Both values are shown with their source; BuildYourCNC supports WF on SBR20.",
   "Left out because no source defines the letters or the sources conflict: the rail's overall height and the shaft's centre height (WF's 'H' and 'h', VEVOR's 'h' and 'H' mean different things), the block's height, the SBR30UU numbers beyond WF, and the SBRL (long) blocks. Treat every value above as a catalog-class number and measure the part you have; SBR is sold by many makers without a controlling standard.",
   "Numbers only: nothing here is drawn, because the support profile (slot, root shape) is not published in any of the three sources.",
   "The round shaft alone (unsupported) is on linear-shafts-h6; the blocks' bushings are LM..UU open type on linear-ball-bushings-lm-uu-luu."
  ],
  "table": {
   "columns": [
    "part",
    "shaft / rail size d, mm",
    "base width of the rail support, mm",
    "width W of the block, mm",
    "length L of the block, mm",
    "block holes B x C, mm (thread)",
    "rail support thickness t, mm / hole spacing across, mm",
    "rail hole diameter / hole pitch along, mm"
   ],
   "rows": [
    [
     "SBR12 rail (supported shaft)",
     "Ø12",
     "32",
     "—",
     "—",
     "—",
     "t 4; across 23 (WF) / 22 (VEVOR)",
     "Ø4.5 (WF) / Ø5 (VEVOR); pitch 100 (WF)"
    ],
    [
     "SBR16 rail (supported shaft)",
     "Ø16",
     "40",
     "—",
     "—",
     "—",
     "t 5; across 30 (WF, VEVOR)",
     "Ø5.5 (WF) / Ø6 (VEVOR); pitch 150 (WF)"
    ],
    [
     "SBR20 rail (supported shaft)",
     "Ø20",
     "45",
     "—",
     "—",
     "—",
     "t 5; across 30 (WF, BuildYourCNC 30.226) / 35 (VEVOR)",
     "Ø5.5 (WF) / Ø6 (VEVOR); pitch 150 (WF, BuildYourCNC)"
    ],
    [
     "SBR25 rail (supported shaft)",
     "Ø25",
     "55",
     "—",
     "—",
     "—",
     "t 6; across 35 (WF) / 40 (VEVOR)",
     "Ø6.5 (WF, VEVOR); pitch 200 (WF)"
    ],
    [
     "SBR30 rail (supported shaft)",
     "Ø30",
     "60",
     "—",
     "—",
     "—",
     "t 7; across 40 (WF)",
     "Ø6.5 (WF); pitch 200 (WF)"
    ],
    [
     "SBR12UU block",
     "Ø12",
     "—",
     "36 (WF) / 40 (VEVOR)",
     "34 (WF) / 39 (VEVOR)",
     "B 26 (WF) / 28 (VEVOR) x C 24 (WF) / 26 (VEVOR) (M5)",
     "—",
     "—"
    ],
    [
     "SBR16UU block",
     "Ø16",
     "—",
     "45",
     "45",
     "B 32 x C 30 (M5)",
     "—",
     "—"
    ],
    [
     "SBR20UU block",
     "Ø20",
     "—",
     "48",
     "50",
     "B 35 x C 35 (M6)",
     "—",
     "—"
    ],
    [
     "SBR25UU block",
     "Ø25",
     "—",
     "60",
     "65",
     "B 40 x C 40 (M6)",
     "—",
     "—"
    ],
    [
     "SBR30UU block",
     "Ø30",
     "—",
     "70 (WF)",
     "70 (WF)",
     "B 50 (WF) x C 50 (WF) (M8 (WF))",
     "—",
     "—"
    ]
   ]
  }
 },
 "sheet_text": "SBR supported linear rails SBR12 to SBR30 and SBR..UU blocks: shaft, base width, hole spacing, hole size, block holes (sources shown where they disagree) — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/sbr-supported-rail-linear-guides-sbr12-sbr30/  (sheet CC BY 4.0)\nBasis: WF International, the VEVOR SBR manual and BuildYourCNC (SBR20 only); only values with a clear meaning are shown and the disagreements are listed\nCatalog version: 2026-10-20\n\nSizes: see table below\n- SBR rails are a shaft of the stated diameter (a hardened, ground round rail) clamped along its length by an aluminium support with a slot, bolted down through holes in the base; SBR..UU is the matching open linear ball bushing block. The family is a de-facto catalog standard (the same sizes appear as SBR, SBS, TBR and TBS from different makers), not an ISO / DIN standard; makers' tables use their own column letters.\n- What is shown and why: three sources were read and the page keeps only values with a clear meaning. WF International (Taiwan, labelled table), the VEVOR product manual (the same numbers in a table whose letters are not defined) and BuildYourCNC for SBR20 alone (labelled: base width 45, hole spacing 30.226 across, 150 along). They agree on the shaft sizes and on the base width of the rail support (WF 'W2' = VEVOR 'B' = 32 / 40 / 45 / 55 for SBR12 / 16 / 20 / 25), its thickness (4 / 5 / 5 / 6) and the blocks' W, L, B, C and thread for SBR16UU, SBR20UU and SBR25UU. They disagree on the hole spacing across the rail for SBR12 (23 vs 22), SBR20 (30 vs 35) and SBR25 (35 vs 40), on the hole diameter (Ø4.5 vs Ø5, Ø5.5 vs Ø6 for SBR12 / 16 / 20), and on every SBR12UU number (W 36 vs 40, L 34 vs 39, B 26 vs 28, C 24 vs 26). Both values are shown with their source; BuildYourCNC supports WF on SBR20.\n- Left out because no source defines the letters or the sources conflict: the rail's overall height and the shaft's centre height (WF's 'H' and 'h', VEVOR's 'h' and 'H' mean different things), the block's height, the SBR30UU numbers beyond WF, and the SBRL (long) blocks. Treat every value above as a catalog-class number and measure the part you have; SBR is sold by many makers without a controlling standard.\n- Numbers only: nothing here is drawn, because the support profile (slot, root shape) is not published in any of the three sources.\n- The round shaft alone (unsupported) is on linear-shafts-h6; the blocks' bushings are LM..UU open type on linear-ball-bushings-lm-uu-luu.\n\npart  shaft / rail size d, mm  base width of the rail support, mm  width W of the block, mm  length L of the block, mm  block holes B x C, mm (thread)  rail support thickness t, mm / hole spacing across, mm  rail hole diameter / hole pitch along, mm\nSBR12 rail (supported shaft)  Ø12  32  —  —  —  t 4; across 23 (WF) / 22 (VEVOR)  Ø4.5 (WF) / Ø5 (VEVOR); pitch 100 (WF)\nSBR16 rail (supported shaft)  Ø16  40  —  —  —  t 5; across 30 (WF, VEVOR)  Ø5.5 (WF) / Ø6 (VEVOR); pitch 150 (WF)\nSBR20 rail (supported shaft)  Ø20  45  —  —  —  t 5; across 30 (WF, BuildYourCNC 30.226) / 35 (VEVOR)  Ø5.5 (WF) / Ø6 (VEVOR); pitch 150 (WF, BuildYourCNC)\nSBR25 rail (supported shaft)  Ø25  55  —  —  —  t 6; across 35 (WF) / 40 (VEVOR)  Ø6.5 (WF, VEVOR); pitch 200 (WF)\nSBR30 rail (supported shaft)  Ø30  60  —  —  —  t 7; across 40 (WF)  Ø6.5 (WF); pitch 200 (WF)\nSBR12UU block  Ø12  —  36 (WF) / 40 (VEVOR)  34 (WF) / 39 (VEVOR)  B 26 (WF) / 28 (VEVOR) x C 24 (WF) / 26 (VEVOR) (M5)  —  —\nSBR16UU block  Ø16  —  45  45  B 32 x C 30 (M5)  —  —\nSBR20UU block  Ø20  —  48  50  B 35 x C 35 (M6)  —  —\nSBR25UU block  Ø25  —  60  65  B 40 x C 40 (M6)  —  —\nSBR30UU block  Ø30  —  70 (WF)  70 (WF)  B 50 (WF) x C 50 (WF) (M8 (WF))  —  —\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- WF International (Taiwan maker): Single shaft rail (SBR / SBRL): H, h, W, L1, B, C, S1 and track W2, P1, t2, hole pitch, hole diameter — web — Publisher's page; dimensions are facts — https://www.wfint.com.tw/Single-Shaft-Rail-1/Single-Shaft-Rail.html\n- VEVOR (product manual PDF): SBR12 to SBR25 rail support and SBRxxUU block dimension tables (column letters not defined in the PDF) — web — Publisher's page; dimensions are facts — https://cdn.shopify.com/s/files/1/1163/1976/files/Vevor_Linear_Guide_Rail_1683713889306_1683768994342-1730150728997..pdf\n- BuildYourCNC: SBR20 supported rail: guide width 20, base width 45, hole spacing 30.226 across and 150 along, overall height 37 — web — Publisher's page; dimensions are facts — https://buildyourcnc.com/Item/mechanical-rails-linear-guide-rails-20mm\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=sbr-supported-rail-linear-guides-sbr12-sbr30\n",
 "sources": [
  {
   "publisher": "WF International (Taiwan maker)",
   "title": "Single shaft rail (SBR / SBRL): H, h, W, L1, B, C, S1 and track W2, P1, t2, hole pitch, hole diameter",
   "url": "https://www.wfint.com.tw/Single-Shaft-Rail-1/Single-Shaft-Rail.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "VEVOR (product manual PDF)",
   "title": "SBR12 to SBR25 rail support and SBRxxUU block dimension tables (column letters not defined in the PDF)",
   "url": "https://cdn.shopify.com/s/files/1/1163/1976/files/Vevor_Linear_Guide_Rail_1683713889306_1683768994342-1730150728997..pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "BuildYourCNC",
   "title": "SBR20 supported rail: guide width 20, base width 45, hole spacing 30.226 across and 150 along, overall height 37",
   "url": "https://buildyourcnc.com/Item/mechanical-rails-linear-guide-rails-20mm",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "linear-shafts-h6",
  "linear-ball-bushings-lm-uu-luu",
  "flanged-linear-bushings-lmf-lmk-lmh",
  "lm8uu-bearing",
  "pillow-block-kp08",
  "hiwin-hg-linear-guideway-hgr-hgh-hgw-15-35",
  "mgn-rails",
  "socket-head-cap-screws-metric"
 ],
 "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": "block holes (SBR16UU / SBR20UU / SBR25UU)",
   "exact": "B x C = 32 x 30 (M5) / 35 x 35 (M6) / 40 x 40 (M6) mm",
   "mates": "carriage plate drilled on the same B x C with clearance for M5 / M6 screws",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "rail base width",
   "exact": "40 / 45 / 55 mm for SBR16 / 20 / 25 (32 for SBR12)",
   "mates": "slot or ledge in the machine bed the support sits on",
   "fit": "designed",
   "files": "all"
  },
  {
   "feature": "shaft diameter",
   "exact": "Ø12 / 16 / 20 / 25 / 30",
   "mates": "SBR..UU open ball bushing bore of the same nominal diameter (linear-ball-bushings-lm-uu-luu)",
   "fit": "run",
   "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 is the base width of an SBR16 rail?",
   "a": "40 mm (WF and VEVOR agree), 5 mm thick, shaft Ø16, with holes Ø5.5 (WF) or Ø6 (VEVOR) 30 mm apart across the rail and 150 mm apart along it."
  },
  {
   "q": "What are the mounting holes of an SBR20UU block?",
   "a": "Four M6 holes, 35 x 35 mm (B x C), block 48 wide and 50 long (WF and VEVOR agree)."
  },
  {
   "q": "Why do the hole spacings differ?",
   "a": "The two catalogs differ for SBR12, SBR20 and SBR25; BuildYourCNC's SBR20 (30.226 across, 150 along) supports the WF value of 30."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/sbr-supported-rail-linear-guides-sbr12-sbr30/index.md"
}