V-belt Size Chart
Figure 1: A banded v-belt.
A v-belt size chart is a convenient resource to have on hand when v-belt replacement is necessary. Through use, a v-belt's label can wear off, making it difficult to identify quickly. As discussed in our v-belt overview article, many different v-belt designs exist. While there are some size similarities between different v-belt sections, there are enough differences to make it difficult to remember the sizes of all the belts. This article provides assistance using v-belt size charts that detail a v-belt's top width, height, and how to determine a belt's part number based on the outside or inside circumference.
Table of contents
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V-belt top width and depth
To determine a v-belt's designation, first determine its section (e.g., A section, BB section, 5V section). To do this, measure the belt's top width and depth. For example, the following measurements designate a Z section v-belt:
- Top width: 10 mm (3/8")
- Height: 6 mm (1/4")
For v-belt size conversion, Table 1 lists metric and imperial measurements for many common v-belt sections. Figure 2 displays the dimensions graphically.
|Section||Top width (mm)||Top width (in)||Height (mm)||Height (in)|
Hexagonal / Double v-belts
Fractional horsepower v-belts
Table 1: V-belt sizes for many common v-belt sections.
Figure 2: Design and sizes of common v-belt sections. Measurements are in millimeters and inches.
A v-belt's label designates its inner circumference. For example, an A20 v-belt is an A section belt with a 20-inch inner circumference. However, without a label, the outer circumference must be measured first to learn the inner circumference. Read our article on v-belt replacement to learn how to measure the outer circumference.
Table 2 shows how the inner or outer circumference of a v-belt can further specify the belt's designation. In Table 2, the values for outer circumference, inner circumference, and v-belt designation are examples. There are many possible values.
The variables in Table 2 are:
- Ci: Inner circumference
- Co: Outer circumference
- k: constant to subtract
|Section||Equation||Outer circumference||Constant to subtract||Inner circumference||V-belt designation|
Ci = Co - k
|SPZ||625 mm||13 mm||612 mm||SPZ612|
|SPA||750 mm||18 mm||732 mm||SPA732|
|SPB||1422 mm||22 mm||1400 mm||SPB1400|
|SPC||2030 mm||30 mm||2000 mm||SPC2000|
C0 X 10
Table 2: Determining a v-belt's designation using outer or inner circumference.
Other letters further indicate a v-belt's construction. Still, these do not impact how the outer or inner circumferences determine part of a v-belt's designation. For example, the letter X indicates that a v-belt is cogged. So an AX22 belt is a cogged A section v-belt with an inner circumference of 22 inches and an outer circumference of 24 inches.
Banded v-belts follow the same designation rules as other v-belts. However, the top width and height designation is for a single band. Also, the designation includes a number that indicates the number of bands. For example, a 2/BX23 v-belt has 2 bands. Each band is cogged and has a top width of 17 mm and a height of 11 mm. Finally, this v-belt has an inner circumference of 23 inches and an outer circumference of 26 inches.
How do you know what size v-belt to get?
To get the proper replacement of a v-belt, measure the used v-belt's top width, height, and outer circumference. For example, a 3L400 v-belt has a 9.5 mm top width, 5.6 mm height, and a 40 inch (1016 mm) outer circumference.
What are the different v-belt sizes?
There are many different v-belt sizes. Some common sizes are standard (Z, A, B, C, D, E), narrow (3V, 5V, 8V), wedge (SPZ, SPA, SPB, SPC), hexagonal (AA, BB, CC), and fractional horsepower (2L, 3L, 4L, 5L).