# V-belt pulley

A solid grooved pulley for classical and narrow V-belts, with a plain bore. The axis is along Z and the first face lies on the XY plane.

The section, datum diameter and number of grooves give the whole pulley:

- the outside diameter is the datum diameter plus 2 b, and the groove bottom diameter is the datum diameter minus 2 h;
- the groove is the datum width wd wide at the datum diameter, with sides at the groove angle α;
- the grooves are e apart, and the outer grooves' centres are f from the faces, so the face width is (grooves - 1) e + 2 f.

| Section | wd | b min | h min | e | f min | Groove angle α by datum Ø dd | dd min |
|---|---|---|---|---|---|---|---|
| Y | 5.3 | 1.6 | 4.7 | 8 | 6 | 32° up to 60, 36° above | 20 |
| Z | 8.5 | 2 | 7 | 12 | 7 | 34° up to 80, 38° above | 50 |
| SPZ | 8.5 | 2 | 9 | 12 | 7 | 34° up to 80, 38° above | 63 |
| A | 11 | 2.75 | 8.7 | 15 | 9 | 34° up to 118, 38° above | 75 |
| SPA | 11 | 2.75 | 11 | 15 | 9 | 34° up to 118, 38° above | 90 |
| B | 14 | 3.5 | 10.8 | 19 | 11.5 | 34° up to 190, 38° above | 125 |
| SPB | 14 | 3.5 | 14 | 19 | 11.5 | 34° up to 190, 38° above | 140 |
| C | 19 | 4.8 | 14.3 | 25.5 | 16 | 34° up to 315, 38° above | 200 |
| SPC | 19 | 4.8 | 19 | 25.5 | 16 | 34° up to 315, 38° above | 224 |
| D | 27 | 8.1 | 19.9 | 37 | 23 | 36° up to 475, 38° above | 355 |
| E | 32 | 9.6 | 23.4 | 44.5 | 28 | 36° up to 600, 38° above | 500 |

The part uses the minimum b, h and f, and the nominal e. A datum diameter under the section's minimum is refused.

## Source

ISO 4183:1995, "Belt drives - Classical and narrow V-belts - Grooved pulleys (system based on datum width)", third edition, 1995-07-01. This is the iTeh Standards public preview of the standard, which carries the whole text: <https://cdn.standards.iteh.ai/samples/25817/ae47c2ed867549cbadc47a63b459cf35/ISO-4183-1995.pdf>. ISO 4183:2026 has since replaced this edition.

- Table 1: datum widths wd.
- Table 2 and figure 1: b min, h min, e, f min.
- Table 4: the groove angle α by datum diameter.
- Table 5: the minimum datum diameter.
- Table 3 lists the preferred datum diameters (R 40). The extra presets use some of them.

**Not from the standard:**

- The standard gives the groove and rim, not the body. This part is a solid pulley with a plain bore, and has no hub, web, keyway or set screw.
- The groove bottom is drawn flat.
- The bore must leave at least 1 mm of wall under the groove bottoms. That's a limit this part sets, not the standard's.
- The extra presets' bores are 0.2 x the datum diameter, for show.
- The materials and colours are a choice: grey cast iron EN-GJL-200 (the default), C45E steel or 6061-T6 aluminium.

## Catalogue models

The old catalogue's `v belt A pulley` and `v belt B pulley` names give an outside diameter and a bore, with one groove. Its model for every one of them was a plain disc, 10 thick, with no groove. This part builds the real pulley for a name where the standard allows one: the datum diameter is the outside diameter minus 2 b, and it must reach table 5's minimum.

- **A section, outside Ø 100 and 120:** datum Ø 94.5 and 114.5, 34°, face width 18, bores 5 to 15. These map.
- **A section, outside Ø 20 to 80:** left out. The datum diameter would be under 75; outside Ø 80 gives 74.5.
- **B section, every outside Ø (20 to 120):** left out. The datum diameter would be under 125, which needs an outside Ø of at least 132.

The old catalogue's flat-belt and round-belt pulleys aren't here. Their model was the same plain disc. Their names give only the outside diameter and bore, not a flat pulley's face width and crown or a round belt's size and groove, so they don't describe one real pulley.