Hi-Cap® sheaves (narrow V-belts) are manufactured from class 30 gray iron (30,000 tensile strength) and can have a maximum speed of 65 fpm. All Martin sheaves are statically balanced. Dynamic balancing should be considered for any sheaves exceeding 50 fpm, or if they will be used on equipment where vibration is a problem. Martin has extensive inventories of both QD and TB style V-belt sheaves to run with 3V, 5V, and 8V belts. Martin Hi-Cap® Wedge Stock Sheave, Arm/Spoke, QD® Bushed Bore, 0.5 to 2.938 in Bore, 19 in OD, 18.95 in Pitch Diameter, 3 Grooves, 1-1/2 in Face Width, SF Bushing, For Use With: 3V-Cross Section V-Belts, Cast Iron