Technical Guides

Complete V-Belt Size Chart & Section Guide

29 May 2026 6 min read

Practical reference chart for V-belt sections, dimensions, widths, and profiles used by workshops, factories, and buyers.

Table of contents

V-belt sections define the belt profile, including top width, height, and the shape that fits the pulley groove. The dimension matters because a belt can be the wrong section even if the length looks close. Correct section selection helps reduce slippage, heat, premature wear, and replacement errors.

Classical V-Belt Sections

Classical sections are the traditional belt families used across many industrial drives. They are identified by their cross-section dimensions and their common pulley compatibility.

SectionTop widthHeightApproximate pitch widthCommon applications
Z10 mm6 mm8.5 mmLight drives, small fans, compact machinery
A13 mm8 mm11 mmGeneral industrial drives, pumps, agricultural equipment
B17 mm11 mm14 mmMedium-duty drives, compressors, machine tools
C22 mm14 mm19 mmHeavier drives, conveyors, crushers, larger pumps
D32 mm19 mm27 mmHeavy-duty plant equipment and large drives
E38 mm23 mm32 mmExtra heavy-duty industrial drives

Classical section notes

  • These sections are widely used where the belt groove and pulley family follow classical dimensions.
  • Width and height both matter when checking the replacement belt.
  • A close length match does not confirm the correct section.

Wedge Belt Sections

Wedge belts use a deeper, more compact profile. The wedge shape can improve grip in suitable pulley grooves and is common in many industrial applications.

SectionTop widthHeightApproximate pitch widthCommon applications
SPZ10 mm8 mm8.5 mmSmall pulley drives, compact machinery
SPA13 mm10 mm11 mmGeneral wedge drives, light industrial use
SPB17 mm14 mm14 mmMedium-duty industrial machinery
SPC22 mm18 mm19 mmLarger wedge drives, conveyors, plant equipment

Wedge profile advantages

  • Better grip in suitable grooves than a flat or mismatched section.
  • Compact shape for drives that need efficient power transmission.
  • Common in industrial systems where pulley design is specified for wedge profiles.

Narrow V-Belt Sections

Narrow sections are designed for higher power transmission in a more compact profile. They are often used where space is limited or where the drive needs a more efficient belt family.

SectionTop widthHeightApproximate pitch widthCommon applications
3V9.5 mm8 mm9.5 mmCompact industrial drives, smaller high-efficiency systems
5V15.9 mm13 mm15.9 mmMedium-power compact drives
8V25.4 mm23 mm25.4 mmLarge high-power industrial drives

Narrow sections are useful when a compact belt must carry more power than a classical profile of similar width.

V-Belt Section Comparison Table

The table below gives a clean reference view of the main belt families and their approximate dimensions.

SectionWidthHeightBelt familyApproximate applications
Z10 mm6 mmClassicalLight drives
A13 mm8 mmClassicalGeneral industrial use
B17 mm11 mmClassicalMedium-duty machinery
C22 mm14 mmClassicalHeavy-duty equipment
D32 mm19 mmClassicalLarge industrial drives
E38 mm23 mmClassicalVery heavy drives
SPZ10 mm8 mmWedgeSmall wedge drives
SPA13 mm10 mmWedgeGeneral wedge applications
SPB17 mm14 mmWedgeMedium wedge drives
SPC22 mm18 mmWedgeLarger wedge systems
3V9.5 mm8 mmNarrowCompact high-efficiency drives
5V15.9 mm13 mmNarrowMedium-power compact drives
8V25.4 mm23 mmNarrowHigh-power industrial drives

How to Identify Belt Sections

Measure the width

Start with the top width. It is one of the most useful first checks when identifying the belt section.

Measure the height

Section height is important because several profiles can have similar widths but different heights.

Read the printed markings

Printed codes such as A45, SPA1250, B72, or 5V900 usually give the fastest clue to the section family.

Avoid common mistakes

  • Measuring a worn belt and assuming the result is the original size.
  • Checking only width and ignoring height.
  • Confusing classical and wedge profiles that look similar.
  • Assuming the pulley will accept any belt that is close in size.

Common V-Belt Applications

V-belt sections are used across many industrial and automotive drives. Common examples include industrial machinery, compressors, textile industry equipment, agricultural machines, and automotive systems.

For section checking, buyers can also use the practical tools on GM Traders such as the V-Belt Section Identifier and the Belt Length Converter.

Common Mistakes

  • Confusing SPA and A section.
  • Measuring worn belts without confirming the marking.
  • Ignoring pulley compatibility.
  • Ordering by width only and skipping the belt family check.

Practical Examples

Example 1

A belt with about 13 mm top width and 8 mm height may indicate A section, especially when the printed marking and pulley profile support that result.

Example 2

A belt with about 17 mm top width and a wedge profile may indicate SPB, depending on the printed marking and actual groove fit.

Why Section Identification Matters

Correct section selection affects pulley fit, slippage, heat, and belt life. A belt that is wrong in section can still look close enough to confuse a buyer, but it may not perform correctly in the drive.

Visual placeholders

  • Section profile diagrams
  • Pulley diagrams
  • Section comparison illustrations

Related resources:

What to confirm before inquiry

  • • Old belt marking
  • • Profile or section
  • • Machine or vehicle application
  • • Quantity and delivery city

Frequently asked questions

What is the difference between SPA and A section?

SPA is a wedge belt section with a narrower profile and different pulley geometry, while A is a classical section. They are not interchangeable by width alone.

Can different sections use the same pulley?

No. A pulley groove must match the belt section closely for proper fit and life.

Why does width matter?

Width affects pulley contact, groove fit, and the section family the belt belongs to.

Why do old belts measure differently?

Old belts can stretch, wear, or deform, so the measured size may differ from the original specification.

Need help matching the correct size?

Send the exact belt marking to GM Traders and we will help confirm the right reference before supply.