Voltage (and possible resistor) required for electromagnet
The resistance of the electromagnet is 53 ohms.


With that information we can, at least, calculate the power dissipated in the coil.

$$ P = \frac {V^2}{R} $$

Note that the square term means the power will rise exponentially with voltage.


At 10 V \$ P = \frac {V^2}{R} = \frac {10^2}{53} = 1.8 \ \text W \$.
At 20 V \$ P = \frac {V^2}{R} = \frac {20^2}{53} = 7.5 \ \text W \$.


It may help to try and think of this in terms of something you are familiar with - say a 6 W car tail light. Can you imagine holding your hand on the powered lamp? What temperature rise would that much heat cause in your electromagnet?

I would be inclined to test it carefully and see if you can hold your hand on it gradually increasing the voltage, if possible.

If you are going to damage it then heat will be the cause.