Thank you for your recent inquiry regarding this item from Prime-Line Products. These knobs are designed to fit on doors with a minimum thickness of 3/4ths of an inch when used with Rosettes, so there are a couple of reasons why you may not be able to screw the knobs in closer to the door… consider these options: 1.) Each knob has 2 Phillips Head set screws that may be obstructing the threads… you’ll want to back all four of these out about an 1/8th of an inch, then try again. 2.) If you’ve already backed out the screws and the knobs are still further away from the door panel than you would like, make sure the Rosettes are installed which will take up some of the free space.
For additional questions regarding this item, or any other product manufactured by Prime-Line Products, please call their toll free number at (877) 649-9740, or contact them by email at email@example.com