We have bolts that are 2.5cm longer than the standard bolts, ie 9cm long bolts. These will allow the knobs to be fixed to doors/drawers that are up to 5cm thick.
Please note that not all knobs can accept a replacement bolt. Only knobs on which you can see the metal bolt head on the face of the knob can have their bolts changed. Knobs with smooth faces have their bolts permanently glued on.
If in doubt, please contact us at email@example.com or on 07746 357625.