Here's what I've found on that subject - from the days an educator could walk into a shop and buy a standard cane.
Nursery cane ΒΌ inch
junior cane 3/8
senior cane 7/16
adult cane / reformatory cane (above 7/16 inch in diameter) or made of dragon rattan
Two types of of a bamboo like plant were used:
kooboo rattan β light and flexible β most common material.
dragon rattan β another type of Rattan that is much denser and produces more pain.
If I recall correctly (and if the source I am thinking was accurate) three dozen was the maximum sentence. Here's a link that seems to confirm it.
See
http://spankingart.org/wiki/Cane for the source of the above information.