A classical V belt is a wedge-shaped industrial belt made in six sections: Z, A, B, C, D and E. The section sets the top width and the height; check the pulley groove against it. The same belt is also written classic V belt.
Key Takeaways
- Classical V belts come in six sections, Z, A, B, C, D and E; the section sets the top width and the height.
- All six share a 40° belt angle, and a distributor catalogue lists minimum pulley diameters from 50 mm for Z to 500 mm for E.
- Sources differ on the A, B and C minimum pulley diameters (71 to 75, 112 to 125 and 180 to 200 mm), so use the maker’s own table.
- The letter names the section and the number names a length; a bare A or B could belong to either the metric or the North American system.
- A match on top width and height does not settle groove or length: check both before you order.
What a classical V belt is
Metric V-belt profiles are grouped into classic sections Z, A, B, C, D and E and narrow sections SPZ, SPA, SPB and SPC (Wikipedia on V-belts). Classical section V belts are the first group.
ISO 4184 sections Z to D line up with DIN 2215 profile numbers 10, 13, 17, 22 and 32 (wrapped classical V-belt datasheet), which equal the top widths in millimeters. E is the widest and tallest section in the catalogue table, at 38 mm top width and 23 mm height (V-belt dimensions and standards catalogue). The guide to V belt types shows where this group sits next to the others.
Classical V belt sections Z to E at a glance
Top width and height, belt angle, datum width and minimum pulley diameter for each classical V belt section:
| Section | Top width × height (mm) | Belt angle | Datum width (mm) | Minimum pulley diameter (mm) |
|---|---|---|---|---|
| Z | 10 × 6 | 40° | 8.5 | 50 |
| A | 13 × 8 | 40° | 11 | 71–75 |
| B | 17 × 11 | 40° | 14 | 112–125 |
| C | 22 × 14 | 40° | 19 | 180–200 |
| D | 32 × 19 | 40° | 27 | 355 |
| E | 38 × 23 | 40° | 32 | 500 |
Sections Z to E, angle and pitch (datum) width: V-belt dimensions and standards catalogue. Z to D also match the wrapped classical V-belt datasheet, which lists 75, 125 and 200 mm as the minimum diameters for A, B and C; the catalogue lists 71, 112 and 180 mm, so both are shown. Other sources differ on the D and E heights: D is 32 × 20 mm in the Turn2Engineering size chart, and the DIN 2215 profile E/40 has a height of 25 mm in a DIN 2215 E/40 profile datasheet.
The belt angle stays 40° in all six rows; pulley grooves are cut at smaller angles on small pulleys (Wikipedia on V-belts). Minimum pulley diameter rises from 50 mm for Z to 500 mm for E (V-belt dimensions and standards catalogue). Sources differ on the A, B and C minimums and on the D and E heights.
How to read the section letter and the size code
Classical V-belt sizes put the section in the letter and a length in the number. In one North American product example, A100, the 100 is the inside circumference in inches (Turn2Engineering V-belt size chart). In the metric system, ISO 4184 uses the datum length Ld, which replaced the old inside length Li (V-belt drive technical manual).
Both systems use the letters A to E, so a bare A or B could mean either until you know which system applies. Length tables and the cross-reference are on the V belt size chart and cross-reference; the V belt length calculation shows how to work a length out from the drive.
How to choose the right classical V belt section
To replace a belt, measure the top width and the perpendicular height at an unworn spot and compare both with the table (Turn2Engineering V-belt size chart). A match on those two dimensions does not settle length, groove, duty or construction, so check which standard the groove was cut to.
For a new drive, a maker’s design manual picks the section from the design horsepower and the rpm of the faster shaft. Near the line between two sections, design with both and take the most economical drive that meets your other requirements (V-belt drive design manual). The same manual warns that diameters below the recommended minimum can reduce belt performance. Pulleys smaller than recommended also raise belt tension and cut belt life (V-belt catalogue with usage tips).
- Read the printed code, or measure the top width and the height.
- Match the section in the table, then check the groove and the smallest pulley against that section’s minimum diameter.
- Check the length basis behind the number in the code.
- Send the code, or a photo of the belt and the groove.
Classical, narrow or cogged: when another profile fits
A narrow profile can share a top width with a classical section and still be taller: SPZ is 10 × 8 mm and SPA is 13 × 10 mm, against 10 × 6 mm for Z and 13 × 8 mm for A (V-belt dimensions and standards catalogue). A section name only identifies a belt family; it gives no general rule for swapping one belt for another (Turn2Engineering V-belt size chart). Cogged belts are covered in classical versus cogged V-belts in industrial drives and in cogged versus classic V-belt performance.
LYBELT’s product range includes classic V-belts. OEM/ODM orders are made to the customer’s part number, drawing or size.
FAQ
What is a classical V belt?
It is a wedge-shaped belt made in six sections, Z, A, B, C, D and E. The letter fixes the top width and height; the number in a size code gives a length. Wikipedia lists the Z to E profiles under the name classic (Wikipedia on V-belts).
What is the difference between A and B section V belts?
A is 13 × 8 mm and B is 17 × 11 mm, both at 40° (V-belt dimensions and standards catalogue). B also needs the larger pulley: 112 mm against 71 mm for A in that catalogue, and 125 mm against 75 mm in a maker datasheet (wrapped classical V-belt datasheet).
What is the minimum pulley diameter for classical V belts?
It rises with the section, from 50 mm for Z to 500 mm for E in a distributor catalogue (V-belt dimensions and standards catalogue). For A, B and C that catalogue lists 71, 112 and 180 mm and a maker datasheet lists 75, 125 and 200 mm (wrapped classical V-belt datasheet), so use the maker’s table for the belt you buy.
Should I keep classical A and B belts or switch to SPA and SPB wedge belts?
An SPA belt has the same 13 mm top width as an A belt but is taller, 10 mm against 8 mm (V-belt dimensions and standards catalogue). A section name gives no general rule for swapping one belt for another, so check the groove before you change profile (Turn2Engineering V-belt size chart).
Can an A section belt be treated as the same as a 4L belt?
Not automatically. A North American classical A belt and a light-duty 4L belt can share the same nominal cross section, but duty, construction, length convention and groove can differ (Turn2Engineering V-belt size chart). A and B also exist in both the metric and the North American systems, so check which standard the groove follows and the length basis.
Sources
- Wikipedia on V-belts
- wrapped classical V-belt datasheet
- V-belt dimensions and standards catalogue
- Turn2Engineering size chart
- DIN 2215 E/40 profile datasheet
- V-belt drive technical manual
- V-belt drive design manual
- V-belt catalogue with usage tips
Source names appear here only as references. LYBELT is not affiliated with them.
About Longyi Rubber Products Factory
LYBELT is the brand of Longyao County Longyi Rubber Products Factory (General Partnership), based in Longyao County, Xingtai, Hebei, China, and making rubber belts since 1999. The factory holds IATF 16949 and ISO 9001 certification and works from 130+ rubber compounds.
The range covers automotive, industrial, agricultural, ATV/UTV and motorcycle belts. For OEM and ODM orders, belts are made to the customer’s part number, drawing or size, with private label and packaging. Email: luxin@lybelt.com.