Ceramic Nuts & Bolts: The pitch diameter of external (male) threads will not exceed the maximum allowable according to the standard. The minimum allowable pitch diameter of external threads may be below that of the standard. Conversely, for internal (female) threads the maximum allowable pitch diameter may be above that of the standard. Due to shrink factor variations in processing, stack-up tolerance cannot be controlled on the pitch. It is recommended not to engage more than 5 to 10 threads on any male fastener.