V-Belt Size report
The v-belt is the most common type of belt as a highly flexible and efficient power transmission device, is readily available at an economical price, and is easy to replace. All V-belts have the feature of allowing multiple free installations. Twisted synthetic fibers compressed by synthetic rubber form a typical V-belt, giving strength and flexibility.
V-belts get their name from their trapezoidal shape, which helps them wedge into the sheaves. V-belts come in cogged construction to break the bending resistance even further, keep the operation temperature lower, and give higher capacity. Unlike chains, V-belts do not require lubrication or maintenance to solve slippage and alignment problems.
Those above unique features make the v-belt the most commonly selected belt for power transmission. The following article introduces the most common v-belt sizes, types, and applications.
V-Belt Types
There are three common V belt types: Classical v-belt classified by their dimensions from A to E; narrow V series organized by their dimensions 3V, 5V, and 8V; FHP light-duty v-belts classified by their sizes 2L, 3L, 4L, 5L. The letter X classifies their counterpart cogged belt. For example, the Classical V cog belt will be 3VX, 5VX, etc.
Classical V-belt
Conventional V-belt is the most common V-belt type and has been around the longest. The general part number format is the cross section size and the inside length in inches. For example, B50 is a B section of 50" inside length.
Narrow V series
Narrow belts are optimum for load transfer and force distribution because of their greater depth to width ratio. Part number designation for narrow belts is shown in belt top width followed by the nominal outside length in inches. The numerical prefix indicates the belt top width in one-eighth of an inch. For example, the 5V500 part number indicates a 5/8" top width with 50.0" outside length.
Fractional Horsepower Belt
FHP light-duty V-belts are designed for relatively light loads. They are identified with a 2L, 3L, 4L, or 5L prefix. The numerical prefix indicates the belt top width in one-eighth of an inch, followed by the nominal outside length in inches. For example, 3L300 part number indicates 3/8" top width with 30.0" outside length.
V-Belt Size Chart
V-Belts come in many sizes and lengths. V-belt cross-sections can be identified by their top width and depth dimensions. For example, a v-belt with a top width of 21/32" and a depth of 7/16" is a "B" belt. The size chart below will help you identify the v-belt.
Standard V-belt Sizes
| V-Belt Type | Top Width | Height | Belt Inside Length (inch) |
|---|---|---|---|
| 3L | 3/8" | 7/32" | 170-1350 |
| 4L | 1/2" | 5/16" | 170-4000 |
| 5L | 5/8" | 13/32" | 230-2680 |
| A | 1/2" | 5/16" | 15-400 |
| B | 5/8" | 13/32" | 20-800 |
| C | 7/8" | 17/32" | 32-800 |
| D | 1.25" | 3/4" | 80-800 |
| E | 1.5" | 29/32" | 105-800 |
| 3VX | 3/8" | 21/64" | 250-1180 |
| 5VX | 5/8" | 35/64" | 410-1380 |
Metric V-belt Sizes
| Belt Type | Top Width | Height | Belt Inside Length(inch) |
|---|---|---|---|
| SPZ | 10mm | 8mm | 20-118 |
| SPA | 13mm | 10mm | 22-138 |
| SPB | 16mm | 13mm | 30-138 |
| SPC | 22mm | 18mm | 250-1180 |
There are many different types of v-belts, so correct measurements are important, but you must also consider what type of v-belt you need. We recommend that you follow these guidelines:
- Identify the cross-section.
- Determine if the v-belt is wrapped or notched style.
- Determine the v-belt length.
It is the best way to consult manufacturer specifications and see their recommendations for correct sizing to ensure that you choose the right v-belt for your application.
