Pan Head Machine screws have a full length thread all the way upto the head of the screw, Measurements are taken from the bottom of the head to the end of the thread.
Example M3 x 12 = 3mm wide screw + 12mm thread length. The heads of these machine screws are pan head giving them a look of rounded edge.
Pitch sizes vary on the thickness of the screw, we have listed the pitch size of fixing in the proctuct information tab on the product listing. Pozi head machine screws are tightened with a cross drive screw driver.