19 is most likely the pitch. A simple tape measure will give you the
diameter for an accurate replacement.

--Mike

"Chris" wrote in message
.. .
I was just wondering if the numbers on a typical prop give you everything
you need in order to replace it?

Or, are there actual measurements that need to be taken?

For example:
a prop with the following code on it:

48 77346 A40 19P

My guess is that 19P may be the pitch?
But what about the rest?

Thanks
Chris