AIW SDK03X1-BN

A: The minimum hole that you could have prepared in your glass door for the AIW SDK03X1-BN Single Brushed Nickel Cylinder Style Shower Door Knob would be 7/16” assuming that youre going to install the plastic bushing (as the OD of the plastic bushing is approximately .378"). If you were to omit the plastic bushing, though this is not recommended, the outside diameter of the bolt is approximately .23”.

My personal recommendation is that you attempted to install it with the bushing that you even reduce the outside dimension by taking material off of the circumference of the plastic bushing if necessary.