All versions of PMC can be fired together as long as the temperature does not go above 1650 degrees F (900 degrees C). These times and temperature schedules refer to the minimum time needed to achieve a dense metal.

These charts show the relative strengths and firing times for the three versions of PMC. Notice that PMC Standard (top, not much dark yellow) has a small window of proper firing, while PMC3 (bottom, lots of dark yellow boxes) achieves full strength as a much wider range of times and temperatures.