The average doorknob have 5.715 cm diameter. Components of door knobs are knob rose, shank, spindle and knob-top. The knob-top is the upper and larger part which is grasped by the hand. The shank is the stem of a knob having a hole or socket which holds the spindle. The knob rose is a round plate forming a knob socket and is ideal for attachment with the surface of a door. Door knobs are made using many materials but brass is most commonly being used, due of its excellent resistance to rust. Diyhandles.com provides exotic range of premium brass door knobs.