Types of V-Belts: V-Belt Selection Guide

There's no doubt why V-belts are the most commonly used belts in power transmission. V-belts provide a solid combination of traction, speed transfer, drive load distribution, and service life. When in use, the trapezoidal or "V" shape of the belt tracks in a groove on a pulley or sheave. The V-belt wedges into the groove as the load increases, and the greater the load, the greater the wedging action—creating power distribution and torque to whatever the V-belt is operating. Typically made from a solid polymer or rubber, some V-belts even have embedded fibers for reinforcement and additional strength. This guide provides basic information about the most common sizes, types, and applications.

V-belts come in a variety of types, including: 

• FHP (Fractional Horsepower) belts are typically used in very low horsepower applications, such as fans.
• A - E belts are used in medium horsepower machines with single-belt and multi-belt drives.
• AX, BX, and CX belts are for medium and high horsepower industrial applications and single-belt and multi-belt drives.
• 3VX and 5VX belts are often used with high horsepower engine drives.
• Banded V-belts provide enhanced stability and load distribution that’s ideal for heavy-duty machinery.
• Micro V-belts have a narrow profile that’s suitable for compact systems such as automotive engines.
• Cogged V-belts feature a toothed design for improved grip and reduced slippage in high-torque applications.
• Link V-belts are versatile, easy to install, and suitable for various types of machinery.
• Multiple V-belts utilize several V-shaped grooves for increased power transmission efficiency. 
• Metric V-belts adhere to international sizing standards, ensuring compatibility across equipment.
• Double V-belts provide traction with two V-shaped surfaces, suitable for demanding industrial environments.
• Variable-speed V-belts offer adjustable performance and are adaptable to fluctuating operating conditions.

• For single-groove, low horsepower applications typically 3HP and under.
• Commonly used in fan applications.

• Used for medium horsepower applications.
• Single- or multi-belt drives and suited for “clutching” applications.
• Longer-wearing than FHP belts, and they transmit more HP than FHP V-belts.

• Medium and high horsepower applications for industrial single or multiple V-belt drives.
• Cogged construction allows the belt to flex around drive sheave and run cooler than the non-cogged standard V-belt design.

• Cogged belt for industrial single or multi V-belt drives.
• Commonly used with high horsepower drives with small sheaves.

Knowing the OEM (Original Equipment Manufacturer) numbers from an existing belt is always the best and simplest way to choose a replacement belt. However, if they are illegible or this is a new installation, there is an easy way to measure belt size.

Take a piece of string that will fit around the belt and wrap it around the drive pulleys the belt will operate in or around the existing belt. Once the end of the string meets the beginning mark, cut the string. Measure with a standard tape measure to get the belt length needed.

Belts can stretch with use over time, so remember to check the sizes of the V-belts available. Adjust to a slightly shorter length to ensure tightness when measuring an existing stretched belt.

To measure the width of the belt, measure across the top of the belt or the groove in which it will rest. Systems with multiple V-belts and pulleys can have the length and width measured individually in a similar fashion.

Once you've selected your correct power transmission belt, check out our selection of belt tighteners and accessories to keep your operations running smoothly.

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions. Portions of this article were generated in part by ChatGPT, and edited by a member of the Zoro team.