A high-lead thread is a thread with a large pitch, where the axial movement per revolution of the spindle is significantly higher than with standard or fine threads. It is used to enable rapid feed rates with minimal force.
High-lead threads are characterized by the following properties:
- High feed rate: large axial movement per revolution
- Lower force transmission: mechanical advantage is lower, not self-locking
- Higher efficiency with ball or roller screw drives, as friction losses are reduced
- Lower positioning accuracy compared to fine threads
Technical Characteristics
- Lead angle greater than with standard threads
- Not self-locking, therefore backdriving can occur in case of load failure
- Frequently used in fast-traversing axes or lifting systems
- With ball screw drives: reduces friction, resulting in lower drive requirements