This Martin FHP sheave BS with a 4L/5L or B belt section is made of 30 gray cast iron and comes with one groove. It is a classical V-belt sheave that fits a variety of widely available, classical profile V-belts suitable for use in many existing power transmission drives. This pulley is made of class 30 gray cast iron for resistance to wear, corrosion, and galling. It has a 4L/5L or B cross section and one groove for use with single belts. V-belt pulleys (sheaves) are used in a wide range of mechanical and electronic drives, including HVAC units, farm machinery, food processing equipment, and home appliances, among others.V-belt pulleys (sheaves) are the component in a power transmission drive that transmits power to the belt. Typically made of cast iron, the pulleys and the V-belts that loop around them match in form – wide (classical) or narrow, single or multi-grooved. V-belt pulleys are found in drive designs in the agriculture, textile, printing, mining, and office equipment industries.Martin Sprocket & Gear manufactures power transmission and conveying products. The company, founded in 1951 and headquartered in Arlington, TX, provides tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.