Bike Steer Column Bolt Size Calculator Bolt Location Faceplate (Holds Handlebars) Steerer Clamp (Back of Stem) Thread Diameter (mm) 5mm (Common M5) 6mm (Common M6) Shank Length (mm) Measure the threaded part only (exclude head). Identify Bolt & Torque Replacement Spec: Hex Key: Max Torque: