Copied from a plain oval knob c.1690+ with a strong steel thread and integral backplate.  You can choose to have the steel thread exposed (visible on the front of the knob) or have a plain brass front (both options can be seen in the photos).

Knob Oval Dimension: Height 1 3/16″ (30mm) – Width 1″ (25mm)

Thread Length: 2″ (50mm)