AK56-1" Sheave Pulley With One Groove OD: 5.6" ID:1" V-Belts size 4L, A, AX, AK561 5.6" Cast Iron Pulley Sheave 1" Shaft One Grooves V Belt A Section 4L AK56-1" Outside diameter: 5.5" inch ~ 5.6" Bore : 1" inch Belt section size: 4L, 3L One Groove One pulley Hex set screws AK561 keyway AK56-1" V-Belt sheaves is an excellent choice for inch and metric shafts. AK Sheaves are accurately machined from fine grained cast iron, statically balanced, painted and individually packaged. The belt series most common for this pulley is 4L, or A , AX, V-Belts.