# Classical V-belts Z, A, B, C, D, E (ISO 4184 / DIN 2215): top width, height, datum width and inside / datum length

> What are the width and height of an A, B or C section V-belt, and how is a belt's length measured (inside length vs pitch / datum length)?

- Category: Hardware › Bearings, rails & motion
- Kind: Standard part
- Basis: Optibelt and ZZR (DIN 2215 / ISO 4184 widths, heights, datum widths), Gates and Tameson (rounded or differing sections), Dayco and ContiTech Li / Ld rows; disagreements shown, numbers only
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**Exact dimensions.** Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part.

## Notes

- Classical (conventional) V-belts are the older wide section: Z, A, B, C, D, E in ISO 4184 / DIN 2215 and RMA IP-20 (the US also uses AX, BX, CX cogged and AA, BB, CC double-V). The letter stands for the section; in the metric designation the number after it is the nominal top width in mm (A/13, B/17, C/22). Top widths and heights are the numbers in the table; the datum width bd is the groove width at the belt's pitch line (the same numbers the ISO 4183 pulley-groove page uses: Z 8.5, A 11, B 14, C 19, D 27, E 32 mm).
- Sources: the Optibelt range sheet and ZZR Parts agree on the DIN 2215 widths and heights (Z 10 × 6, A 13 × 8, B 17 × 11, C 22 × 14, D 32 × 20, E 40 × 25). Gates' catalogue prints D 32 × 19 and E 38 × 25 (E top width 38 instead of 40); Tameson prints D 19 and E 40 × 25. Where they differ both are shown; the belt's maker catalogue is the authority for its own belt. Inch sections are as printed by VBeltSupply (A 1/2 × 5/16, B 21/32 × 7/16, C 7/8 × 17/32, D 1-1/4 × 3/4) and Tameson (B 13/32).
- Length conventions. Classical belts are sold by inside length Li (RMA: 'A68' = 68 in inside length, 'B75' = 75 in) or in the ISO / European system by datum length Ld (the length at the pitch line; 'pitch length' is the older name for the same thing). Ld = Li + an add-on that depends on the section. The add-ons below are what two brands print: Dayco (one example per section, Li to Ld, in mm): Z +25, A +33, B +40, C +59, D +76, E +81; ContiTech (every row read, constant per section): A +30 mm, B +45 mm. The two systems differ (A +33 vs +30, B +40 vs +45) and C to E add-ons come from one brand only, so use your belt maker's table, not a single add-on. Outside length La (measured with a tape over the top) is approximate; Aims Industrial gives Z 1, A 2, B 3, C 4, D 5, E 6 in as the outside-to-inside deduction.
- Not on this page: sizes between the sections (Y, 5, 8, 20, 25), the 40° belt-angle tolerance, per-length tables, tolerances and matching. McMaster-Carr's V-belt category is linked below for per-belt CAD.
- Li to Ld examples as printed: Z16DR (Dayco): Li 406 → Ld 431 mm (+25); A16DR (Dayco): Li 406 → Ld 439 mm (+33); B22DR (Dayco): Li 559 → Ld 599 mm (+40); C43DR (Dayco): Li 1092 → Ld 1151 mm (+59); D79DR (Dayco): Li 2007 → Ld 2083 mm (+76); E144DR (Dayco): Li 3658 → Ld 3739 mm (+81); A60 (ContiTech): Li 1525 → Ld 1555 mm (+30); A82 (ContiTech): Li 2083 → Ld 2113 mm (+30); A98 (ContiTech): Li 2500 → Ld 2530 mm (+30); B35 (ContiTech): Li 889 → Ld 934 mm (+45); B43 (ContiTech): Li 1090 → Ld 1135 mm (+45); B67 (ContiTech): Li 1700 → Ld 1745 mm (+45).

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| datum width bd | Z 8.5, A 11, B 14, C 19, D 27, E 32 mm | pulley groove datum width wd (ISO 4183): see v-belt-pulley-grooves-iso-4183-narrow | designed | all |

## Sizes

| section (RMA letter / ISO width) | top width b0, mm (DIN 2215 / ISO 4184 tables) | datum width bd, mm (ZZR) | height h, mm (ISO tables) | Gates width × height, mm | inch top width × height as printed | differences between sources |
|---|---|---|---|---|---|---|
| Z / 10 | 10 | 8.5 | 6 | 10 × 6 | 3/8 × 1/4 (Tameson) | Dayco Z16DR, Tameson 10 × 6 |
| A / 13 | 13 | 11 | 8 | 13 × 8 | 1/2 × 5/16 (VBeltSupply, Tameson) | Dayco 'A: Profile (13mm X 8mm)' |
| B / 17 | 17 | 14 | 11 | 17 × 11 | 21/32 × 7/16 (VBeltSupply); 21/32 × 13/32 (Tameson) | the two inch heights differ: 7/16 in is 11.1 mm, 13/32 in is 10.3 mm |
| C / 22 | 22 | 19 | 14 | 22 × 14 | 7/8 × 17/32 (VBeltSupply, Tameson) | — |
| D / 32 | 32 | 27 | 20 (Optibelt, ZZR); 19 (Gates, Tameson) | 32 × 19 | 1-1/4 × 3/4 (VBeltSupply, Tameson) | height 19 vs 20 mm: sources differ |
| E / 40 | 40 (Optibelt, ZZR, Tameson); 38 (Gates) | 32 | 25 | 38 × 25 | 1-1/2 × 29/32 (VBeltSupply, Tameson) | top width 40 vs 38 mm: sources differ |

## Where the files are

- Optibelt: [Belt range: classical V-belt table (DIN 2215 / ISO 4184 width b, height h, Li / Ld) and wedge / narrow belt tables](https://santent.in/wp-content/uploads/2020/08/Optibelt-Belt-Range.pdf) — web — Publisher's page; dimensions are facts
- ZZR Parts: [Classic V-series (DIN 2215 / ISO 4184): top width bo, datum width bd, height h](https://www.zzr-parts.com/?p=944) — web — Publisher's page; dimensions are facts
- Gates (Statewide Bearings copy): [Industrial V-belt catalogue: section widths and heights, datum and outside lengths](https://www.statewidebearings.com.au/wp-content/uploads/2018/06/Gates-Industrial-V-Belts-1.pdf) — web — Publisher's page; dimensions are facts
- VBeltSupply: [Belt spec guide: inch top width x height for classical, 3V / 5V / 8V, SPZ to SPC; length designation examples](https://www.vbeltsupply.com/media/wysiwyg/guides/belt-spec-guide.pdf) — web — Publisher's page; dimensions are facts
- Tameson: [V-belt size chart: top width and height of Z, A, B, C, D, E, 3V, 5V, 8V, SPZ, SPA, SPB, SPC](https://tameson.com/v-belt-size-chart.html) — web — Publisher's page; dimensions are facts
- 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](https://na.daycoaftermarket.com/wp-content/uploads/IND-DR-VB-PG-0619-Industrial-Product-Guide.pdf) — web — Publisher's page; dimensions are facts
- acorn-ind.co.uk (ContiTech listing): [Wrapped classical V-belt rows with Li and Ld in mm (A, B)](https://www.acorn-ind.co.uk/contitech/power-transmission/industrial-belts/v-belts/wrapped-classical-v-belts/?start=240) — web — Publisher's page; dimensions are facts
- acorn-ind.co.uk (ContiTech listing): [Wrapped classical V-belt rows with Li (in) and Ld (mm)](https://www.acorn-ind.co.uk/power-transmission/industrial-belts/v-belts/wrapped-classical-v-belts/?start=600) — web — Publisher's page; dimensions are facts
- Aims Industrial: [How to measure a V-belt: Li, La, Ld definitions; narrow-section inside-to-pitch length additions](https://aimsindustrial.com.au/blogs/product-guides/blog-how-to-measure-a-v-belt) — web — Publisher's page; dimensions are facts
- ISO: [ISO 4184:2025 Belt drives, classical and narrow V-belts, lengths in datum system (standard; sold, not reproduced)](https://www.iso.org/standard/88704.html) — standard — ISO; dimensions are facts (verify at link)
- McMaster-Carr: [V-belts (classical, narrow, banded) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/c81-v-belts) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**How wide is an A-section V-belt?**

13 mm (1/2 in) top width and 8 mm (5/16 in) high; datum width 11 mm.

**How wide is a B-section V-belt?**

17 mm (21/32 in) top width, 11 mm high (7/16 in; Tameson prints 13/32 in); datum width 14 mm.

**What is the difference between inside length and pitch length?**

Inside length Li is measured round the inner face; pitch (datum) length Ld at the belt's pitch line. Ld = Li + a section-dependent add-on: ContiTech prints +30 mm for A and +45 mm for B, Dayco +33 and +40.

## Fits with

- [Narrow V-belts 3V, 5V, 8V and SPZ, SPA, SPB, SPC (wedge belts): top width, height, datum width and length designation](https://xemstudio.com/objects/v-belts-narrow-3v-5v-8v-spz-spa-spb-spc/)
- [V-belt pulley grooves ISO 4183: SPZ, SPA, SPB, SPC datum width, groove spacing, angle and minimum diameter](https://xemstudio.com/objects/v-belt-pulley-grooves-iso-4183-narrow/)
- [Timing belt profiles: GT2, HTD 3M / 5M / 8M, T5, T10, AT5, MXL, XL, L, H: pitch, tooth height and pulley pitch diameter](https://xemstudio.com/objects/timing-belt-profiles-pitch-and-tooth/)
- [Taper-Lock bushings 1008 to 5050: bore range, length through bore, set screw and cap screw sizes](https://xemstudio.com/objects/taper-lock-bushings-1008-to-5050/)
- [QD bushings SH, SDS, SD: length, bolt circle, flange diameter and cap screws](https://xemstudio.com/objects/qd-bushings-sh-sds-sd/)
- [Parallel keys DIN 6885 form A: 2 × 2 to 18 × 11, with keyway depths](https://xemstudio.com/objects/parallel-keys-din-6885/)