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 5 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, Solid Type A-1, QD® Bushed Bore, 0.5 to 1.688 in Bore, 4.12 in OD, 4.7 in Pitch Diameter, 3 Grooves, 1-1/2 in Face Width, SH Bushing, 1-3/8 in Overall Length, For Use With: 3V-Cross Section V-Belts, Steel