(Note: Measurements are outside max. dimensions unless stated otherwise).19th Century : Decorative knob with gently domed top with star pattern and indentation centre top.Top diam. 14mm. (9/16")Height 15mm. (9/16") + threaded shaft 10mm. (3/8")Collar diam. 8mm. (5/16")For suitable backplate if required, see "Backplates" section.It is recommended that a pilot hole is drilled and pre-cut with a steel screw of slightly smaller size before screwing in the casting to avoid shearing.