Vee belts, or V-belts, are a common type of drive belt for pulley systems or power transmission drives. V-belts are so-called because they are tapered on either side. Their cross sections are either v-shaped,coming to a point on the inner side of the belt; or trapezoidal, with a narrow, flat surface on the inside of the belt. Some V-belts have ribs or cog inlets at regular intervals, while others have totally smooth surfaces.

V-belts are of various materials, including a range of reinforcements. There are also V-belt sheaves, which is where multiple belts band together to act as a single, high-traction belt. An important V-belt specification is the cross section shape, often noted by Records Management Application (RMA) standards. There are some variations, but these are the main dimension ratio names:

1. These are the standard English shapes: O/3L/Z, A/4L, B/5L, C, D, E, 3V, 5V, and 8V.

2. These are the shapes for metric V-belts: SPA, SPB, SPZ, 5mm, 6mm, 8mm, 10mm, 13mm, 17mm, 20mm, 22mm, 25mm, 32mm, and 40mm.

3. These are the shapes for ribbed V-belts: H, J, L, M, and PK.

Action Steps
The best contacts and resources to help you get it done

Know what to look for in an industrial V-belt

V-belts suppliers carry belts with many material and reinforcement options. Obviously, these belts are also available with varying lengths, but remember to take into account that V-belt pulleys allow for the adjustable V-belt fit. Besides these basic parameters, you should also pay attention to max operating speed and overall tensile strength if they are published.

I recommend: There are many sources for V-belts, so shop around to find the best prices; however, Grainger is a solid source to begin with. They carry classic V-belts, as well as cogged. Another source is H.V.A.C. Maintenance & Supplies. They do have a minimum order requirement, however.

Buy specialty V-belts

riations to accommodate an even wider array of applications. Double V-belts are double sided, having a taper on both sides to form a hexagonal cross section. In other words, both sides of a double V-belt are drive sides. There are also variable speed V-belts which are unusually wide in order to maintain traction during speed shifts. There are also cogged V-belts, which are actually quite common and noted by an 'X' in the shape designation.

I recommend: Gates Corporation carries low-profile and specialty surface V-belts, as well as especially high performance belts. If you are prepared to try something totally different, check out the NuTLink belts sold by Fenner Drives. These belts are a sort of chain/belt hybrid that outperform many traditional V-belts.

Locate the correct replacement V-belts

Regularly check the inside surface of your V-belts for cracking. Don't wait too long to replace worn belts, as this could translate to machinery down time or worse.

I recommend: Especially for industrial applications, shopping for a replacement belt is the same as shopping for a first time use belt. However for appliances and such you may have to go to an application specific source like Instawares Restaurant Supply Superstore where you can find the exact part for your unit. To replace your automotive V-belt, try Gates Corporation or a dedicated auto parts source like Auto Parts Warehouse.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  V-belts are best for applications where speed ratio is somewhat flexible. They are not intended for high-tolerance applications.