Bought the knobs for an update to painted cabinets to carry me through rather than a complete kitchen remodel. Older, cheaper cabinets, manufacturer unknown. Knobs come with 2 inches screws that were too long for my cabinet doors. I had 26 knobs so I purchased screws in a 50 pack and got 1.75 inch screws. Because of the knob threading not starting immediately at the end (it's concave about a quarter of an inch under the part that sits against the cabinet), the screw won't go in all the way. It also might be caused by the threading not going as far through the knob consistently - I have about 4 that I cannot get any tighter. The ideal length of screw should be about 1.5 inches : quarter to reach the knob, quarter to go in the knob and about an inch to go through your cabinet. Still like the look of them!