Adjusting Tightener Arm Length to Hole Center 4 in For Shaft Thread Size 3/4 In.-10 Includes Tightener Shaft No Mount Base Length Not Applicable Mount Base Width 1 5/8 in Mount Hole Diameter 1 in Overall Length 6.25 in Shaft Diameter Not Applicable Shaft Length Not Applicable Shaft Thread Size 3/4 In.-10 Thread Length Not Applicable Compatible Idler Pulley Grainger Part Number 6AGN9 (Timing) 6AGP1 (Timing) 6AGP2 (Flat) 6AGP3 (Flat) 6AGP6 (V-Belt) 6AGP7 (V-Belt) 6AGP8 (V-Belt)