You are currently viewing 25 Uses for LEFT-HAND GRADE 8 TAP BOLTS


Grade 8 tap bolts, including those with a left-hand thread, are high-strength fasteners commonly used in various applications where strong, secure joints are needed. The “left-hand” designation refers to the direction in which the bolt tightens, which is counter-clockwise, opposite to the more common right-hand threaded bolts. Here are 25 uses for left-hand grade 8 tap bolts:

  1. Rotating Machinery: Preventing loosening in machines where components rotate counter-clockwise.
  2. Automotive Flywheels: Securing flywheels in vehicles, where reverse threading is required to prevent loosening.
  3. Bicycle Pedals: Specifically on the left pedal to prevent unwinding under normal pedaling forces.
  4. Safety Applications: In critical systems where vibration could loosen right-hand threaded bolts.
  5. Repairing Damaged Threads: By re-tapping stripped holes with a left-hand thread for new bolts.
  6. Conveyor Systems: In certain conveyor belt systems to maintain tension and prevent loosening.
  7. Wind Turbines: For securing components that experience reverse rotational forces.
  8. Precision Instruments: In devices requiring specific assembly orientations to maintain calibration.
  9. Gas and Oil Drilling Equipment: Where reverse rotation is used and bolts must remain secure under high stress.
  10. Marine Propellers: On boats, particularly on propeller shafts, to counteract rotational loosening.
  11. Motorcycle Drive Chains: In specific motorcycle models to ensure sprockets remain tight.
  12. Adjustment Mechanisms: In systems that require precise adjustments through the opposite movement of threaded components.
  13. Aerospace Applications: In aircraft and spacecraft, where reliability and resistance to vibration are critical.
  14. Racing Vehicles: In high-performance cars and motorcycles where every component’s reliability is crucial.
  15. Heavy Machinery: For securing parts in construction equipment and tractors to withstand vibration and stress.
  16. Agricultural Equipment: In farm machinery, where parts are exposed to high stress and reversing loads.
  17. Mining Equipment: Securing components that experience intense vibrations and reversing forces.
  18. Robotic Arms: In automation and robotics, where precise control and reliability are necessary.
  19. Industrial Fans: In large-scale ventilation systems to ensure blades remain securely attached.
  20. Centrifuges: In laboratory and industrial centrifuges, where secure fastening is essential for safety.
  21. Gearboxes: In transmissions and gearboxes to prevent bolts from loosening due to the gear rotation.
  22. Pump Assemblies: Securing components in pump systems, particularly where reverse flow is possible.
  23. Railway Equipment: For fastening parts in railway systems that are subject to vibrations and reversing loads.
  24. Power Generation Equipment: In generators and turbines where reliability under high stress is critical.
  25. Structural Assemblies: In buildings and bridges, especially in joints and connections that could be subjected to rotational or reversing forces.


These uses highlight the wide range of applications for left-hand Grade 8 tap bolts across various industries, including automotive, aerospace, industrial machinery, and more. Their high strength and unique threading make them an invaluable component in ensuring the safety, reliability, and longevity of mechanical systems and structures.

Allied Bolt and Screw Corporation, a Small Business incorporated in the Commonwealth of Massachusetts by Richard ‘Dick’ Goldberg, has been building strong relationships since 1961 with an expansive quality inventory, exceptional service and highly valued customer appreciation. Allied carries Left Handed Grade 8 Tap Bolts and thousands of other products. Contact Us for more information.