Specification Brand : TB Woods BulletPoint1 : Classical V-belt sheave fits widely available, classical profile V-belts suitable for use in many existing drive designs BulletPoint2 : Cast iron for resistance to wear and galling BulletPoint3 : B belt or cross section BulletPoint4 : Two grooves for multiple or banded belt use BulletPoint5 : Note - For the stiffness of the thin pulley shaft, it is recommended to choose a 4mm belt for a pulley shaft below 8mm and a 5mm belt for a pulley shaft above 8mm. BulletPoint6 : Package Contents:1 x Roller Chain Sprocket,2 x Screws,1 x Wrench Color : Silver Tone ExternallyAssignedProductIdentifier1 : 698672150972 ExternallyAssignedProductIdentifier2 : 0698672150972 ExternallyAssignedProductIdentifier3 : 00698672150972 ItemName : TB Woods 2BK45118 FHP Bored-to-size V-Belt Sheave, B Belt Section, 2 Grooves, 1-1/8" Bore, Cast Iron, 4.25" OD, 5890 max rpm ItemPackageDimensions_Height : 6.35 centimeters ItemPackageDimensions_Length : 11.684 centimeters ItemPackageDimensions_Width : 12.954 centimeters ItemPackageQuantity : 1 ItemShape : Round ItemTypeKeyword : v-belt-pulleys Manufacturer : TB Woods Material : Cast Iron MaximumRotationalSpeed : 5890 rpm ModelNumber : 698672150972 NumberOfItems : 1 NumberOfTeeth : 21 PartNumber : 2BK45118 ProductDescription : The V-Type single groove motor pulley is made of aluminum alloy, with small precision error, high-speed rotation without shaking, effectively suppressing transmission noise and fluctuations, and improving the stability of the belt operation. The V-shaped Single Groove pulley is suitable for 4-5MM PU round belts, 90° top screw fastening design, can adapt to a wide range of round optical axes, single flat shaft, 90° double D axis, 180° double D axis, suitable for DIY small drilling machines, Milling machines, small unpowered spindles of machine tools, can also be used for most fitness equipment. This series of pulleys can be combined with any two adjacent pulleys upside down. For example, if a diameter 31 pulley and a diameter 41 pulley with the same aperture are installed on the motor, a double-layer pulley can be formed. With two sets of such pulleys, you can DIY small two-speed drilling machines, milling machines, and unpowered spindles for small lathes. Notice: The thicker the belt, the greater the transmission power can be, but the bending flexibility of the belt is also greater. For the stiffness of the thin shaft, it is recommended to choose a 4mm belt for a shaft below 8mm and a 5mm belt for a shaft above 8mm. In addition, the belt with a diameter of 4mm can be selected for the short center distance, and the belt with a diameter of 5mm can be selected for the larger one to obtain better transmission performance.