Specification Brand : HARFINGTON BulletPoint1 : Size - Aperture Diameter: 25mm; Outer Diameter: 80mm; Overall Thickness: 18.5mm; Groove Width: 7mm; Groove Depth: 4.4mm; Step Thickness: 8.5mm; Step Diameter: 42mm; Applicable Belts: 6mm PU round belt. BulletPoint2 : Material - The single-groove pulley is made of aluminum alloy, with small precision error, stable operation, high-speed rotation without shaking, effectively suppressing transmission noise and fluctuations, and improving the stability of the belt operation. BulletPoint3 : Usage - First, you need to measure the diameter of the shaft to be installed. For example, if the diameter of the shaft is 8 mm, the inner diameter of the pulley should be 8 mm, so that the installation will be just right. BulletPoint4 : Application - Silver aluminum alloy single slot is suitable for motors, micro spindles, model transmission design, motor shaft transmission, etc. BulletPoint5 : Note - A belt pulley with an outer diameter of 16mm is not suitable for use together with other sizes of belt pulleys. Color : Silver Tone ExternallyAssignedProductIdentifier1 : 0849230059521 ExternallyAssignedProductIdentifier2 : 849230059521 ItemName : HARFINGTON Single Groove Pulley 25mm Fixed Bore 80mm Outer Diameter Aluminum Alloy with Hex Wrench for Drilling Machine 6mm PU Round Belt ItemPackageDimensions_Height : 0.79 inches ItemPackageDimensions_Length : 5.51 inches ItemPackageDimensions_Width : 3.94 inches ItemPackageQuantity : 1 ItemShape : Round ItemTypeKeyword : round-belt-pulleys Manufacturer : HARFINGTON Material : Aluminum Alloy NumberOfItems : 1 PartNumber : hta230820hh000339 ProductDescription : The single-groove pulley is made of aluminum alloy, with small precision error, stable operation, high-speed rotation without shaking, effectively suppressing transmission noise and fluctuations, and improving the stability of the belt operation. Silver aluminum alloy single slot is suitable for motors, micro spindles, model transmission design, motor shaft transmission, etc. First, you need to measure the diameter of the shaft to be installed. For example, if the diameter of the shaft is 8 mm, the inner diameter of the pulley should be 8 mm, so that the installation will be just right. Notice: A belt pulley with an outer diameter of 16mm is not suitable for use together with other sizes of belt pulleys.