In article , "Trevor" wrote:
I am trying to identify a taper on a drive centre and it does not appear to
be a Morse taper. The dimensions I have are as follows:

Length of taper 40mm (1.575")
Large diameter 12mm (0.472")
Small diameter 10.27mm (0.404")

Amount of taper: 0.068"
Taper per inch of length: 0.0432-


I measured the diameters as near the end of the taper as I could so please
do not take these measurements as gospel - they are there or thereabouts.

I suspect the taper is metric but I cannot find a source to prove this.

Can anyone offer any help?

I think you have a #1 Morse taper. I measured one of mine:
length of taper 1.850"
large diameter 0.500"
small diameter 0.420"
amount of taper: 0.080"
taper per inch of length: 0.0432+

In other words, the degree of taper on yours is essentially the same as the
degree of taper on mine. Yours has a bit more at the narrow end than mine,
and a bit less at the fat end, and it's shorter overall, but the angles are
the same. I *know* mine is a #1 Morse. Sounds to me like yours is too.