V-Belt Size Chart & Cross Section Reference
V-Belt Size Chart & Cross Section Reference
This page is the complete reference for identifying V-belt cross sections by their dimensions. Use it to determine the section letter from a belt's top width and depth, find the correct part number format for each section family, and confirm which sheave groove profile matches your belt. Every standard industrial V-belt cross section is covered: classical, cogged, narrow wedge, cogged narrow wedge, FHP/light duty, banded, and double-V.
If you have a belt in hand but no readable part number, measure the top width and depth, find the matching row in the chart below, then measure the outside circumference to determine the length. Or send us a photo and measurements and we will identify it. Call 888-203-2358.
Jump to Section Family
Complete V-Belt Cross Section Chart
| Section | Top Width | Depth | Type | HP Range | Min. Sheave OD | Part Number Format | Length Basis |
|---|---|---|---|---|---|---|---|
| Classical V-Belts (Wrapped) | |||||||
| A | 1/2" (12.7 mm) | 5/16" (8 mm) | Classical | 1/4 - 10 | 3.0" | A[length] (e.g. A68) | Inside length, OC minus 2 |
| B | 5/8" (16 mm) | 13/32" (10.5 mm) | Classical | 1 - 25 | 5.4" | B[length] (e.g. B100) | Inside length, OC minus 3 |
| C | 7/8" (22 mm) | 17/32" (13.5 mm) | Classical | 15 - 100 | 9.0" | C[length] (e.g. C120) | Inside length, OC minus 4 |
| D | 1-1/4" (32 mm) | 3/4" (19 mm) | Classical | 50 - 250 | 13.0" | D[length] (e.g. D240) | Inside length, OC minus 5 |
| E | 1-1/2" (38 mm) | 1" (25.4 mm) | Classical | 100 - 500+ | 21.6" | E[length] (e.g. E360) | Inside length, OC minus 7 |
| Cogged V-Belts (Raw Edge) | |||||||
| AX | 1/2" (12.7 mm) | 5/16" (8 mm) | Cogged | 1/4 - 10 | 2.2" | AX[length] (e.g. AX45) | Inside length, OC minus 2 |
| BX | 5/8" (16 mm) | 13/32" (10.5 mm) | Cogged | 1 - 25 | 4.0" | BX[length] (e.g. BX62) | Inside length, OC minus 3 |
| CX | 7/8" (22 mm) | 17/32" (13.5 mm) | Cogged | 15 - 100 | 7.0" | CX[length] (e.g. CX120) | Inside length, OC minus 4 |
| Narrow Wedge V-Belts | |||||||
| 3V | 3/8" (9.5 mm) | 5/16" (8 mm) | Narrow | 1/2 - 25 | 2.65" | 3V[OC x 10] (e.g. 3V355) | Outside circumference x 10 |
| 5V | 5/8" (15.9 mm) | 17/32" (13.5 mm) | Narrow | 10 - 100 | 7.1" | 5V[OC x 10] (e.g. 5V1060) | Outside circumference x 10 |
| 8V | 1" (25.4 mm) | 7/8" (22 mm) | Narrow | 50 - 500+ | 12.5" | 8V[OC x 10] (e.g. 8V1700) | Outside circumference x 10 |
| Cogged Narrow Wedge V-Belts | |||||||
| 3VX | 3/8" (9.5 mm) | 5/16" (8 mm) | Cogged Narrow | 1/2 - 25 | 2.2" | 3VX[OC x 10] (e.g. 3VX355) | Outside circumference x 10 |
| 5VX | 5/8" (15.9 mm) | 17/32" (13.5 mm) | Cogged Narrow | 10 - 100 | 5.5" | 5VX[OC x 10] (e.g. 5VX1000) | Outside circumference x 10 |
| 8VX | 1" (25.4 mm) | 7/8" (22 mm) | Cogged Narrow | 50 - 500+ | 10.0" | 8VX[OC x 10] (e.g. 8VX1700) | Outside circumference x 10 |
| FHP / Light Duty V-Belts | |||||||
| 2L | 1/4" (6.4 mm) | 3/16" (4.8 mm) | FHP | Under 1/4 | 0.75" | 2L[OC x 10] (e.g. 2L250) | Outside circumference x 10 |
| 3L | 3/8" (9.5 mm) | 7/32" (5.6 mm) | FHP | Under 1/2 | 1.0" | 3L[OC x 10] (e.g. 3L350) | Outside circumference x 10 |
| 4L | 1/2" (12.7 mm) | 5/16" (8 mm) | FHP | Under 1 | 1.5" | 4L[OC x 10] (e.g. 4L590) | Outside circumference x 10 |
| 5L | 21/32" (16.7 mm) | 3/8" (9.5 mm) | FHP | Under 2 | 2.5" | 5L[OC x 10] (e.g. 5L700) | Outside circumference x 10 |
| Banded V-Belts | |||||||
| Banded A-E | Per base section | Per base section | Banded | Per base section | Per base section | [bands]/[section][length] (e.g. 3/B68) | Inside length per base section |
| Banded 3V-8V | Per base section | Per base section | Banded | Per base section | Per base section | [bands]/[section][OC x 10] (e.g. 2/5V1060) | Outside circumference x 10 |
| Double-V (Hex) Belts | |||||||
| AA | 1/2" (12.7 mm) | 5/8" (15.9 mm) | Double-V | Per application | 3.0" | AA[length] (e.g. AA68) | Inside length |
| BB | 5/8" (16 mm) | 13/16" (20.6 mm) | Double-V | Per application | 5.4" | BB[length] (e.g. BB100) | Inside length |
| CC | 7/8" (22 mm) | 1-1/16" (27 mm) | Double-V | Per application | 9.0" | CC[length] (e.g. CC120) | Inside length |
How to Measure a V-Belt in 3 Steps
Step 1: Measure Top Width (Determines Section)
Lay the belt flat and measure straight across the widest surface (the top of the belt). Use a ruler or caliper. Match the measurement to the chart above to determine the section letter.
| Top Width | Classical | Cogged | Narrow Wedge | FHP |
|---|---|---|---|---|
| 1/4" | 2L | |||
| 3/8" | 3V / 3VX | 3L | ||
| 1/2" | A | AX | 4L | |
| 5/8" | B | BX | 5V / 5VX | |
| 21/32" | 5L | |||
| 7/8" | C | CX | ||
| 1" | 8V / 8VX | |||
| 1-1/4" | D | |||
| 1-1/2" | E |
Step 2: Measure Depth (Confirms Section)
Measure from the top surface straight down to the bottom of the V shape. Do not measure along the angled sidewall. This depth, combined with the top width, confirms the exact section.
- 1/2" wide x 5/16" deep = A / AX / 4L (distinguish by construction: fabric cover = A, raw edge cogs = AX, light duty = 4L)
- 5/8" wide x 13/32" deep = B / BX (classical profile, shallower)
- 5/8" wide x 17/32" deep = 5V / 5VX (narrow wedge profile, deeper)
- 7/8" wide x 17/32" deep = C / CX
- 1" wide x 7/8" deep = 8V / 8VX
Step 3: Measure Outside Circumference (Determines Length)
Wrap a flexible tape measure around the outside (top surface) of the belt. This gives you the outside circumference (OC). Then apply the correct formula for your section family:
| Section Family | Formula | Example |
|---|---|---|
| Classical A / AX | Part number = OC minus 2 | OC 70" → A68 or AX68 |
| Classical B / BX | Part number = OC minus 3 | OC 103" → B100 or BX100 |
| Classical C / CX | Part number = OC minus 4 | OC 124" → C120 or CX120 |
| Classical D | Part number = OC minus 5 | OC 245" → D240 |
| Classical E | Part number = OC minus 7 | OC 367" → E360 |
| Narrow (3V, 5V, 8V) | Part number = OC x 10 | OC 106.0" → 5V1060 |
| Cogged Narrow (3VX, 5VX, 8VX) | Part number = OC x 10 | OC 100.0" → 5VX1000 |
| FHP (2L, 3L, 4L, 5L) | Part number = OC x 10 | OC 59.0" → 4L590 |
Sheave Groove Compatibility
A V-belt must be paired with a sheave that has the correct groove profile. Using the wrong belt in a sheave groove causes poor grip, excessive wear, noise, and premature failure.
| Belt Section | Compatible Sheave Groove | Interchangeable With |
|---|---|---|
| A / AX | A groove | A and AX are interchangeable on the same sheave |
| B / BX | B groove | B and BX are interchangeable on the same sheave |
| C / CX | C groove | C and CX are interchangeable on the same sheave |
| D | D groove | D only |
| E | E groove | E only |
| 3V / 3VX | 3V groove | 3V and 3VX are interchangeable on the same sheave |
| 5V / 5VX | 5V groove | 5V and 5VX are interchangeable on the same sheave |
| 8V / 8VX | 8V groove | 8V and 8VX are interchangeable on the same sheave |
| 2L, 3L, 4L, 5L | FHP groove (per section) | FHP only. 4L fits A groove in some cases but not recommended. |
Frequently Asked Questions
Measure the top width and depth. Match both measurements to the cross section chart above. Top width alone is not always enough because multiple sections share the same width (A and 4L are both 1/2" wide; B and 5V are both 5/8" wide). The depth measurement distinguishes them. If the belt has raw rubber sidewalls with molded notches on the bottom, it is a cogged belt (add "X" to the section letter).
Inside length is measured around the inner (bottom) surface of the belt. Outside circumference (OC) is measured around the outer (top) surface. Classical V-belt part numbers (A, B, C, D, E) use inside length. Narrow wedge (3V, 5V, 8V) and FHP (2L-5L) part numbers use outside circumference multiplied by 10. This is the most common source of ordering errors. Always check which system your section uses.
Both 4L and A belts are 1/2" wide x 5/16" deep, and a 4L belt will physically fit in an A groove. However, FHP belts are built to lighter construction standards than industrial A-section belts and are not rated for the same loads. Using a 4L on a drive designed for A-section belts risks premature failure. Use the belt type specified for your drive.
Measure the depth. A B-section belt is 13/32" (10.5 mm) deep. A 5V belt is 17/32" (13.5 mm) deep. The 5V is noticeably deeper for the same top width. Also check the sheave: B and 5V grooves are shaped differently. Using the wrong belt in the wrong groove causes poor fit and accelerated wear.
If you cannot remove the belt, measure the top width and depth on an accessible section. For length, measure the sheave diameters and center distance, then use the belt length formula: L = 2C + 1.57(D+d) + (D-d)^2/(4C), where C = center distance, D = large sheave diameter, d = small sheave diameter. Or call Texas Belting at 888-203-2358 with the sheave diameters and center distance and we will calculate the correct belt length.
Yes. Send a photo showing the belt cross section (end view showing the V shape), any remaining markings, and a ruler or coin for scale. Include the top width and outside circumference measurements if possible. Our team identifies belts every day and can usually confirm the correct part number within the hour during business hours. Email sales@texasbelting.com or call 888-203-2358.
Related Pages
Still Not Sure Which V-Belt You Need?
Send us a photo, part number, or measurements and Texas Belting will identify your belt and quote a replacement. We identify belts every day and stock every standard section from multiple manufacturers.
Get Help Call 888-203-2358