Fastener Thread Designations and Definitions Pitch, Minor, Major Diameters

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Pitch, Minor, Major Diameters
  • Major Diameter is the largest material diameter of a thread or gear tooth feature.
  • Minor Diameter is the smallest material diameter of a thread or gear tooth feature.
  • Pitch Diameter is a diameter between the major and minor diameter where the medium area contact with the associated thread or gear occurs.