1.68 Milimeters
Bronze
The thickness of a penny is approximately 1.52 mm.
Millimetres to 1 decimal place (or micrometres rounded to the nearest 100).
There was never an Australian pre decimal coin (pre-1966) minted with a Koala on the front, back, or anywhere else.
Pre-decimal British Pennies were made from bronze from 1860 until 1967.
The height of a penny is the thickness: 1.55 mm (millimeters)
The decimal value is 0.080
19mm, Thickness is 1.55mm
1.55mm at the rim
Half a penny in decimal form is 0.005
It is highly unlikely for a wheat penny to be half the thickness of a regular penny. It is possible that the coin may be worn down due to circulation, but a significant difference in thickness may indicate a counterfeit or altered coin.
A decimal halfpenny is written and was spoken as it sounds here - it is no longer in-circulation in the UK. The pre-decimal halfpenny was also written as one word, but was spoken like: "hayp'nny."