Light-Duty FHP V-Belts — 2L to 5L

What it is

FHP belts are made for single-belt drives on small motors. They are designed to bend around small sheaves and to work on drives that are often not tensioned closely. They are not built to the matched tolerances of industrial multiple-belt sets. Common uses include furnace blowers, evaporative coolers, lawn and garden equipment, compressors and shop machines.

How to identify

The marking gives the section and length, such as 4L360. The section number rises with belt size. Many FHP belts have a printed cover and some are raw-edge or cogged. If the marking is gone, measure the outside length with a tape or belt measuring tool and the top width with calipers, then compare to the V-belt cross-section chart.

Decoding FHP belt numbers

Drop the last digit to get the outside length in whole inches. The last digit is tenths of an inch.

FHP vs classical belts

4L and A belts, and 5L and B belts, have similar top widths and often run in the same sheaves. They are not the same belt. A and B belts are numbered by approximate inside length; 4L and 5L belts are numbered by outside length. A 4L belt and an A belt with similar numbers are different lengths. Classical belts are also built for heavier, multi-belt service.

Key points

• Use FHP belts on single-belt, light-duty drives. Use classical or narrow belts on industrial multi-belt drives.
• Replace with the same section and length. A belt that is too long will slip; too short may not fit or will overload bearings.
• Heavy-duty or cogged FHP belts run cooler on small sheaves.
• Check pulley alignment and sheave wear when a belt fails early.

Common mistakes

• Using an A belt to replace a 4L belt with the same number.
• Running a light-duty FHP belt on an industrial multi-belt drive.
• Over-tensioning small motor drives, which wears motor bearings.
• Ignoring a glazed or cracked belt on a furnace blower until it fails.

Governing standards: ARPM IP-23 (light-duty or fractional horsepower V-belts); belt maker's catalog. See the V-belt cross-section chart.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.