Single V-Belts

Classical

Cross Section | W | T |

A, AX, AK | 1/2" | 5/16" |

B, BX, BK | 21/32" | 13/32" |

C, CX, CK | 7/8" | 17/32" |

D | 1 1/4" | 3/4" |

Classical belts constructed from pre-stretched polyester cord (A, B, C, D). "X" designates molded cogged
construction (AX, BX, CX). "K" designates Thunder Classical V-Belts®, heavy-duty belts constructed from
aramid tensile cord (AK, BK, CK). For belt part number, use Inside Circumference (IC). To calculate IC,
measure Outside Circumference (OC) and subtract the following values: A- subtract 2", B- subtract 3",
C- subtract 4", D- subtract 5". For part number on belt over 210" measure OC and subtract the following values:
B- subtract 1.5", C- subtract 2", D- subtract 2.5". Example: A30= 1/2" wide; 30" IC (32" OC)

Wedge

Cross Section | W | T |

3V, 3VX, 3VK | 3/8" | 21/64" |

5V, 5VX, 5VK | 5/8" | 35/32" |

8V, 8VX, 8VK | 1" | 7/8" |

Wedge belts constructed from pre-stretched polyester cord (3V, 5V, 8V). "X" designates molded
cogged construction (3VX, 5VX). "K" designates Thunder Wedge V-Belts®, heavy-duty belts
constructed from aramid tensile cord (3VK, 5VK, 8VK). For belt part number, use OC measurement
to the tenth of an inch. Example: 3V425= 3/8" wide; 42.5" OC

Metric

Cross Section | W | T |

SPZ, SPZX, XPZ | 10mm | 8mm |

SPA, SPAX, XPA | 13mm | 10mm |

SPB, SPBX, XPB | 16mm | 13mm |

SPC, SPCX, XPC | 22mm | 18mm |

Metric belts constructed from pre-stretched polyester cord (SPZ, SPA, SPB, SPC). "X" designates molded
cogged construction (SPZX or XPZ, SPAX or XPA, SPBX or XPB, SPCX or XPC). For belt part number,
use OC and subtract the following values: Z- subtract 13mm, A- subtract 18mm, B- subtract 22mm,
D- subtract 30mm. Example: SPA1600= 13mm wide; 1618mm OC

FHP

Cross Section | W | T |

3L | 3/8" | 7/32" |

4L | 1/2" | 5/16" |

5L | 21/32" | 3/8" |

Fractional Horsepower (FHP) belts constructed from pre-stretched polyester cord (3L, 4L, 5L). For belt
part number, use OC measurement to the tenth of an inch. Example: 4L400= 1/2" wide; 40.0" OC

Banded V-Belts

Classical

Classical V-Belts bound together with a
fabric tie band. For belt part number,
indicate the number of ribs and Classical
V-Belt part number.
Example: 4/C225= 4 rib C225

Wedge

Wedge or Thunder Wedge V-Belts
bound together with a fabric tie band.
For belt part number, indicate number
of ribs and Wedge V-Belt part number.
Example: 4/8V3150= 4 rib 8V3150

Double Sided V-Belts

Double Sided

Cross Section | W | T |

AA | 1/2" | 13/32" |

BB/td> | 21/32" | 17/32" |

CC | 7/8" | 11/16" |

Double Sided V-Belts, known as hexagonal belts, are constructed from pre-stretched polyester cord
(AA, BB, CC). For belt part number, use OC and subtract the following values: AA- subtract 3.3",
BB- subtract 4.7", CC- subtract 6.2".
Example: AA55= 1/2" wide; 58.3" OC

V-Ribbed Belts

V-Ribbed

Three parts make up a V-Ribbed Belt
part number: OC measurement to
the tenth of an inch, belt cross section
letter, and number of ribs.
Example: 360J6= 36.0" OC; J-section;
6 ribs wide