How to determine Torque from these motor numbers?

Howdy all again.. hope everyone is having a great holiday.

I have some Ametek DC motora here with a few more specs. How do i
derive the Torque from these numbers, or is more data needed?
So far I have found out:

Resistance is about 1.7 Ohm, useing the following readings when
applying the following to the motor with the shaft locked:

10.5V drew 6.5A = 1.6 Ohm
16.5V drew 9A = 1.8 Ohm
(my meters wont go above 10A reading)

"30VDC nominal" is printed on the motor, but seems to want to run at
higher voltages.. it is OK to run it above 30VDC?
No load resulted in these numbers:

30V .58A = 720 RPM
50V .67A = 1260 RPM
60V .73A = 1500 RPM

Like I said, Id like to know the Torque of these motors, as well as
if they are a good canidate for a small/medium CNC mill project
useing Geckos. Ball screws are yet to be obtained.

Thanks for any help (again). :)
Colin