External ACME thread dimensions chart per ASME/ANSI B1.5 standard.
Major Diameter: The maximum diameter of a thread which is diameter of the crest of a male thread or root of a female thread.
Minor Diameter: The minimum diameter of a thread which is diameter of the root of a male thread or crest of a female thread.
Thread class: A classification system to classify the threads for interchangeability and manufacturability.
Threads per inch: Number of full thread per an inch length.