What are the belt models?
2 Answers
National standards specify seven types of V-belts: O, A, B, C, D, E, and F. Pulley groove angles: They are divided into 32 degrees, 34 degrees, 36 degrees, and 38 degrees. The specific selection depends on the pulley groove type and the reference diameter; the pulley groove angle is related to the pulley diameter. Different types of pulleys have different groove angles within various diameter ranges: For O-type pulleys, the groove angle is 34 degrees when the pulley diameter ranges from 50mm to 71mm; 36 degrees when the diameter is between 71mm and 90mm; and 38 degrees when it exceeds 90mm. For A-type pulleys, the groove angle is 34 degrees when the diameter ranges from 71mm to 100mm; 36 degrees between 100mm and 125mm; and 38 degrees when it exceeds 125mm. For B-type pulleys, the groove angle is 34 degrees when the diameter ranges from 125mm to 160mm; 36 degrees between 160mm and 200mm; and 38 degrees when it exceeds 200mm. For C-type pulleys, the groove angle is 34 degrees when the diameter ranges from 200mm to 250mm; 36 degrees between 250mm and 315mm; and 38 degrees when it exceeds 315mm. For D-type pulleys, the groove angle is 36 degrees when the diameter ranges from 355mm to 450mm; and 38 degrees when it exceeds 450mm. For E-type pulleys, the groove angle is 36 degrees when the diameter ranges from 500mm to 630mm; and 38 degrees when it exceeds 630mm.
When it comes to belt models, I've seen too many car owners get confused. There are two main types of automotive belts: one is the multi-ribbed belt, which has several ribs on the side, with model numbers like 5PK1230—the first number represents the number of grooves, and the last four digits indicate the length in millimeters; the other is the V-belt, marked similarly as A46.5, where the letter represents the cross-sectional width and the number indicates the outer circumference in inches. Different brands have different naming conventions: Gates prefers simple numeric codes like T275, Continental starts its models with CT, such as CT997, while Bando uses BD as the prefix. The key is to refer to the original vehicle manual and the actual parameters printed on the belt for selection, otherwise, it won't fit, and that would be embarrassing. I've seen someone force-install a belt that was 3mm off in size, and it snapped within six months.
