These were purchased for a writing desk that I was going to restore but it turned out to be un-repairable, the knobs have been stored since and some threads do have tiny rust makes but the nut has no problem tightening up.

The knob is 4 cm in diameter and 7 cm long. the thread from the back of the knob to the part that will be inside your drawer is about 3 cm.

From a smoke free home.