Replacement 3-way Nickel standard turn knob sockets have uno threads and nickel plated shells and caps with set screws. Nickel sockets use 3-way light bulbs. Lamp sockets are tapped 1/8 IP and fit standard lamp pipe. The nickel finish blends well with vintage silver or nickel lamps.
Before making any changes to electrical fixtures and lamps:
Disconnect plug/wire from the electrical source.
Turning lamp off will not protect you from electric shock.
If you are unsure how to safely proceed contact a licensed electrician.