{
 "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": "v-belts-narrow-3v-5v-8v-spz-spa-spb-spc",
 "name": "Narrow V-belts 3V, 5V, 8V and SPZ, SPA, SPB, SPC (wedge belts): top width, height, datum width and length designation",
 "kind": "standard",
 "category": "Hardware",
 "group": "Bearings, rails & motion",
 "year": null,
 "question": "What are the width and height of an SPZ, SPA, SPB, SPC, 3V, 5V or 8V V-belt, and how are they sized (datum length mm or outside length in tenths of an inch)?",
 "tags": [
  "v-belt",
  "wedge belt",
  "narrow v belt",
  "spz",
  "spa",
  "spb",
  "spc",
  "3v",
  "5v",
  "8v",
  "iso 4184",
  "rma ip-20"
 ],
 "aliases": [
  "spz belt dimensions",
  "spa belt dimensions",
  "spb belt dimensions",
  "spc belt dimensions",
  "3v belt width",
  "5v belt width",
  "8v belt width",
  "3v vs spz belt",
  "5v vs spb belt",
  "narrow v belt size chart",
  "wedge belt cross section",
  "spb belt 16.3 x 13",
  "spz belt 9.7 x 8",
  "3v250 belt length",
  "v belt datum length spz",
  "optibelt spa belt width"
 ],
 "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/v-belts-narrow-3v-5v-8v-spz-spa-spb-spc/",
 "sheet_txt": "https://xemstudio.com/objects/v-belts-narrow-3v-5v-8v-spz-spa-spb-spc/sheet.txt",
 "sheet": {
  "basis": "Optibelt (ISO 4184 / ISO 4183 narrow sections), Gates, Dayco, VBeltSupply, Tameson and GPR Industrial; sources disagree by up to 1 mm and all are shown; numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Narrow (wedge) V-belts carry more power in less width than classical belts. Metric sections SPZ, SPA, SPB, SPC (ISO 4184 narrow) are designated by the datum length Ld in mm; the US sections 3V, 5V, 8V (RMA IP-20; 9N, 15N, 25N in Optibelt's naming) are designated by outside length in tenths of an inch (3V250 is 25.0 in). SPZ and 3V, SPB and 5V are close in size but are different belts and different grooves: they are not interchangeable.",
   "Where the sources disagree (they do, by up to 1 mm in top width): Optibelt's table, which follows ISO 4184, prints SPZ 9.7, SPA 12.7, SPB 16.3 and SPC 22 mm wide; Gates' catalogue, VBeltSupply and GPR Industrial print the rounded 10, 13, 17, 22 mm; Tameson prints 9.7 / 12.7 / 17 / 22. For 3V / 5V / 8V: Optibelt 9 / 15 / 25 × 8 / 13 / 23, Gates 10 / 17 / 26 × 8 / 13 / 23 (printed as SPZ-3V, SPB-5V, 8V), Dayco 3V 9.5 × 8, VBeltSupply 3/8 / 5/8 / 1 in wide and 21/64 / 35/64 / 7/8 in high, Tameson 9.7 / 15.8 / 25.4 × 8 / 14 / 23. Heights agree within 1 mm. All the numbers are shown; none is chosen as 'the' size.",
   "Datum width (wd) is the groove width at the datum line from ISO 4183, as used on the pulley-groove page (SPZ 8.5, SPA 11, SPB 14, SPC 19 mm); 3V, 5V and 8V sheaves follow RMA / MPTA groove tables, which are not tabulated here. Aims Industrial prints inside-to-pitch length additions for the narrow metric sections: SPZ 13 mm, SPA 18 mm, SPB 22 mm, SPC 30 mm (single source; use your maker's table). Gates' Powerband catalogue prints 3V / 5V / 8V rib pitches of 10.30, 17.50 and 28.60 mm and SPB / SPC 19.00 and 25.50 mm for banded belts.",
   "Groove / belt angle: Aims Industrial states a 40° belt angle for A and SPZ; a US belt retailer describes SP belts with a 38° wedge angle (that is the ISO 4183 pulley-groove angle for larger diameters, not the belt angle). No angle is tabulated here for that reason.",
   "Not on this page: banded (Powerband) widths, cogged raw-edge (XPZ, XPA, XPB, 3VX, 5VX) variations, tolerances and matching, belt length tables, minimum sheave diameters. McMaster-Carr's V-belt category is linked below for per-belt CAD."
  ],
  "table": {
   "columns": [
    "section",
    "Optibelt / ISO, top width × height, mm",
    "Gates, mm",
    "Dayco / VBeltSupply inch (mm in brackets)",
    "Tameson, mm",
    "datum width wd, mm (ISO 4183)",
    "length designation"
   ],
   "rows": [
    [
     "SPZ",
     "9.7 × 8",
     "10 × 8 (listed with 3V)",
     "10 × 8 mm (VBeltSupply)",
     "9.7 × 8",
     "8.5",
     "datum length Ld, mm (e.g. SPZ 767)"
    ],
    [
     "SPA",
     "12.7 × 10",
     "13 × 10",
     "13 × 10 mm (Dayco, VBeltSupply)",
     "12.7 × 10",
     "11",
     "datum length Ld, mm"
    ],
    [
     "SPB",
     "16.3 × 13",
     "17 × 13 (listed with 5V)",
     "17 × 13 mm (VBeltSupply)",
     "17 × 13",
     "14",
     "datum length Ld, mm"
    ],
    [
     "SPC",
     "22 × 18",
     "22 × 18",
     "22 × 18 mm (VBeltSupply)",
     "22 × 18",
     "19",
     "datum length Ld, mm"
    ],
    [
     "3V / 9N",
     "9 × 8 (9N)",
     "10 × 8 (listed with SPZ)",
     "3/8 × 21/64 in (VBeltSupply, 9.5 × 8.3); 9.5 × 8 mm (Dayco)",
     "9.7 × 8",
     "—",
     "outside length in tenths of an inch (3V250 = 25.0 in; Dayco 3V250DR 25.00 in)"
    ],
    [
     "5V / 15N",
     "15 × 13 (15N)",
     "17 × 13 (listed with SPB)",
     "5/8 × 35/64 in (VBeltSupply, 15.9 × 13.9)",
     "15.8 × 14",
     "—",
     "outside length in tenths of an inch (5V620 = 62.0 in, VBeltSupply)"
    ],
    [
     "8V / 25N",
     "25 × 23 (25N)",
     "26 × 23",
     "1 × 7/8 in (VBeltSupply, 25.4 × 22.2)",
     "25.4 × 23",
     "—",
     "outside length in tenths of an inch"
    ]
   ]
  }
 },
 "sheet_text": "Narrow V-belts 3V, 5V, 8V and SPZ, SPA, SPB, SPC (wedge belts): top width, height, datum width and length designation — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/v-belts-narrow-3v-5v-8v-spz-spa-spb-spc/  (sheet CC BY 4.0)\nBasis: Optibelt (ISO 4184 / ISO 4183 narrow sections), Gates, Dayco, VBeltSupply, Tameson and GPR Industrial; sources disagree by up to 1 mm and all are shown; numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Narrow (wedge) V-belts carry more power in less width than classical belts. Metric sections SPZ, SPA, SPB, SPC (ISO 4184 narrow) are designated by the datum length Ld in mm; the US sections 3V, 5V, 8V (RMA IP-20; 9N, 15N, 25N in Optibelt's naming) are designated by outside length in tenths of an inch (3V250 is 25.0 in). SPZ and 3V, SPB and 5V are close in size but are different belts and different grooves: they are not interchangeable.\n- Where the sources disagree (they do, by up to 1 mm in top width): Optibelt's table, which follows ISO 4184, prints SPZ 9.7, SPA 12.7, SPB 16.3 and SPC 22 mm wide; Gates' catalogue, VBeltSupply and GPR Industrial print the rounded 10, 13, 17, 22 mm; Tameson prints 9.7 / 12.7 / 17 / 22. For 3V / 5V / 8V: Optibelt 9 / 15 / 25 × 8 / 13 / 23, Gates 10 / 17 / 26 × 8 / 13 / 23 (printed as SPZ-3V, SPB-5V, 8V), Dayco 3V 9.5 × 8, VBeltSupply 3/8 / 5/8 / 1 in wide and 21/64 / 35/64 / 7/8 in high, Tameson 9.7 / 15.8 / 25.4 × 8 / 14 / 23. Heights agree within 1 mm. All the numbers are shown; none is chosen as 'the' size.\n- Datum width (wd) is the groove width at the datum line from ISO 4183, as used on the pulley-groove page (SPZ 8.5, SPA 11, SPB 14, SPC 19 mm); 3V, 5V and 8V sheaves follow RMA / MPTA groove tables, which are not tabulated here. Aims Industrial prints inside-to-pitch length additions for the narrow metric sections: SPZ 13 mm, SPA 18 mm, SPB 22 mm, SPC 30 mm (single source; use your maker's table). Gates' Powerband catalogue prints 3V / 5V / 8V rib pitches of 10.30, 17.50 and 28.60 mm and SPB / SPC 19.00 and 25.50 mm for banded belts.\n- Groove / belt angle: Aims Industrial states a 40° belt angle for A and SPZ; a US belt retailer describes SP belts with a 38° wedge angle (that is the ISO 4183 pulley-groove angle for larger diameters, not the belt angle). No angle is tabulated here for that reason.\n- Not on this page: banded (Powerband) widths, cogged raw-edge (XPZ, XPA, XPB, 3VX, 5VX) variations, tolerances and matching, belt length tables, minimum sheave diameters. McMaster-Carr's V-belt category is linked below for per-belt CAD.\n\nsection  Optibelt / ISO, top width × height, mm  Gates, mm  Dayco / VBeltSupply inch (mm in brackets)  Tameson, mm  datum width wd, mm (ISO 4183)  length designation\nSPZ  9.7 × 8  10 × 8 (listed with 3V)  10 × 8 mm (VBeltSupply)  9.7 × 8  8.5  datum length Ld, mm (e.g. SPZ 767)\nSPA  12.7 × 10  13 × 10  13 × 10 mm (Dayco, VBeltSupply)  12.7 × 10  11  datum length Ld, mm\nSPB  16.3 × 13  17 × 13 (listed with 5V)  17 × 13 mm (VBeltSupply)  17 × 13  14  datum length Ld, mm\nSPC  22 × 18  22 × 18  22 × 18 mm (VBeltSupply)  22 × 18  19  datum length Ld, mm\n3V / 9N  9 × 8 (9N)  10 × 8 (listed with SPZ)  3/8 × 21/64 in (VBeltSupply, 9.5 × 8.3); 9.5 × 8 mm (Dayco)  9.7 × 8  —  outside length in tenths of an inch (3V250 = 25.0 in; Dayco 3V250DR 25.00 in)\n5V / 15N  15 × 13 (15N)  17 × 13 (listed with SPB)  5/8 × 35/64 in (VBeltSupply, 15.9 × 13.9)  15.8 × 14  —  outside length in tenths of an inch (5V620 = 62.0 in, VBeltSupply)\n8V / 25N  25 × 23 (25N)  26 × 23  1 × 7/8 in (VBeltSupply, 25.4 × 22.2)  25.4 × 23  —  outside length in tenths of an inch\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Optibelt: Belt range: classical V-belt table (DIN 2215 / ISO 4184 width b, height h, Li / Ld) and wedge / narrow belt tables — web — Publisher's page; dimensions are facts — https://santent.in/wp-content/uploads/2020/08/Optibelt-Belt-Range.pdf\n- Gates (Statewide Bearings copy): Industrial V-belt catalogue: section widths and heights, datum and outside lengths — web — Publisher's page; dimensions are facts — https://www.statewidebearings.com.au/wp-content/uploads/2018/06/Gates-Industrial-V-Belts-1.pdf\n- Dayco: Industrial product guide: V-belt Li and Ld examples per section, A 13 x 8, 3V 9.5 x 8, SPA 13 x 10 — web — Publisher's page; dimensions are facts — https://na.daycoaftermarket.com/wp-content/uploads/IND-DR-VB-PG-0619-Industrial-Product-Guide.pdf\n- VBeltSupply: Belt spec guide: inch top width x height for classical, 3V / 5V / 8V, SPZ to SPC; length designation examples — web — Publisher's page; dimensions are facts — https://www.vbeltsupply.com/media/wysiwyg/guides/belt-spec-guide.pdf\n- Tameson: V-belt size chart: top width and height of Z, A, B, C, D, E, 3V, 5V, 8V, SPZ, SPA, SPB, SPC — web — Publisher's page; dimensions are facts — https://tameson.com/v-belt-size-chart.html\n- Aims Industrial: How to measure a V-belt: Li, La, Ld definitions; narrow-section inside-to-pitch length additions — web — Publisher's page; dimensions are facts — https://aimsindustrial.com.au/blogs/product-guides/blog-how-to-measure-a-v-belt\n- ISO: ISO 4184:2025 Belt drives, classical and narrow V-belts, lengths in datum system (standard; sold, not reproduced) — standard — ISO; dimensions are facts [verify license at link] — https://www.iso.org/standard/88704.html\n- McMaster-Carr: V-belts (classical, narrow, banded) (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/c81-v-belts\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=v-belts-narrow-3v-5v-8v-spz-spa-spb-spc\n",
 "sources": [
  {
   "publisher": "Optibelt",
   "title": "Belt range: classical V-belt table (DIN 2215 / ISO 4184 width b, height h, Li / Ld) and wedge / narrow belt tables",
   "url": "https://santent.in/wp-content/uploads/2020/08/Optibelt-Belt-Range.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Gates (Statewide Bearings copy)",
   "title": "Industrial V-belt catalogue: section widths and heights, datum and outside lengths",
   "url": "https://www.statewidebearings.com.au/wp-content/uploads/2018/06/Gates-Industrial-V-Belts-1.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Dayco",
   "title": "Industrial product guide: V-belt Li and Ld examples per section, A 13 x 8, 3V 9.5 x 8, SPA 13 x 10",
   "url": "https://na.daycoaftermarket.com/wp-content/uploads/IND-DR-VB-PG-0619-Industrial-Product-Guide.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "VBeltSupply",
   "title": "Belt spec guide: inch top width x height for classical, 3V / 5V / 8V, SPZ to SPC; length designation examples",
   "url": "https://www.vbeltsupply.com/media/wysiwyg/guides/belt-spec-guide.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Tameson",
   "title": "V-belt size chart: top width and height of Z, A, B, C, D, E, 3V, 5V, 8V, SPZ, SPA, SPB, SPC",
   "url": "https://tameson.com/v-belt-size-chart.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Aims Industrial",
   "title": "How to measure a V-belt: Li, La, Ld definitions; narrow-section inside-to-pitch length additions",
   "url": "https://aimsindustrial.com.au/blogs/product-guides/blog-how-to-measure-a-v-belt",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ISO",
   "title": "ISO 4184:2025 Belt drives, classical and narrow V-belts, lengths in datum system (standard; sold, not reproduced)",
   "url": "https://www.iso.org/standard/88704.html",
   "formats": [
    "standard"
   ],
   "license": "ISO; dimensions are facts",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "McMaster-Carr",
   "title": "V-belts (classical, narrow, banded) (free STEP/IGES per part, for your own design use; no redistribution)",
   "url": "https://www.mcmaster.com/c81-v-belts",
   "formats": [
    "STEP",
    "IGES",
    "PDF"
   ],
   "license": "McMaster-Carr site terms: personal design use, no redistribution",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "v-belts-classical-z-a-b-c-d-e",
  "v-belt-pulley-grooves-iso-4183-narrow",
  "timing-belt-profiles-pitch-and-tooth",
  "taper-lock-bushings-1008-to-5050",
  "qd-bushings-sh-sds-sd",
  "parallel-keys-din-6885"
 ],
 "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": "datum width wd (SPZ / SPA / SPB / SPC)",
   "exact": "8.5 / 11 / 14 / 19 mm",
   "mates": "pulley groove datum width wd (ISO 4183): see v-belt-pulley-grooves-iso-4183-narrow",
   "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 wide is an SPB belt?",
   "a": "16.3 mm per ISO 4184 (Optibelt); 17 mm in Gates, VBeltSupply and Tameson; 13 mm high; datum width 14 mm."
  },
  {
   "q": "Is a 3V belt the same as an SPZ belt?",
   "a": "No. They are close (about 9.5 to 10 mm wide, 8 mm high) but are different standards with different grooves; sources print 3V as 9, 9.5, 9.7 or 10 mm wide."
  },
  {
   "q": "How is a 5V belt length given?",
   "a": "Outside length in tenths of an inch: 5V620 is 62.0 in around the outside."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/v-belts-narrow-3v-5v-8v-spz-spa-spb-spc/index.md"
}