Metric Screw Thread Table

FAQ

• What is the difference between coarse and fine metric threads?
  Coarse threads have larger pitch values and are used for general applications where quick assembly is needed. Fine threads have smaller pitch values, providing better holding power and are used in precision applications or where vibration resistance is important.
• How do I read metric thread designations like "M5×0.8"?
  The "M" indicates metric thread, "5" is the major diameter in millimeters, and "0.8" is the pitch (distance between threads) in millimeters. For coarse threads, the pitch can be omitted (e.g., "M5" implies M5×0.8).
• Why can the pitch be omitted for coarse threads?
  Coarse threads are the most common type for each diameter, so the pitch is standardized and can be omitted. For example, M5 automatically means M5×0.8. Fine threads must always specify the pitch because multiple fine pitch options exist for each diameter.
• What does the 60° thread angle mean?
  The 60° angle refers to the included angle between the thread flanks. This angle is standardized for metric threads and provides the optimal balance between strength, manufacturing ease, and thread engagement. It's measured between the two sides of the thread profile.
• How do I use the table filters to find specific thread information?
  Use the dropdown filters above the table columns to narrow down results by designation (thread size) and pitch. Switch between "Coarse" and "Fine" tabs to view different thread series. The table is responsive and searchable for quick reference.
• Are metric threads compatible with imperial (inch) threads?
  No, metric and imperial threads are not interchangeable. They have different thread angles (60° vs 60°), different pitch systems (mm vs TPI), and different diameter standards. Always verify thread type before assembly to avoid damage.