Greenfield Tap tech tip of tapping titanium from Cutting Tools Chicago aka General Cutting Tools. Titanium and titanium alloys are most often found in aerospace applications due to their light weight and high strength. However, other industries are discovering the benefits of titanium as well.
One of the characteristics that makes titanium difficult to tap is its tremendous elastic memory. During tapping, the material closes tightly around the cutting tool, generating friction and heat, and resulting in increased wear of the cutting edges. This material also easily work hardens.
To successfully tap titanium, consider the following:
- Choose a tap specifically designed with additional clearance to overcome the extreme elastic memory of the material. Tap clearances would include extra back taper of the threads from the front to the back of the thread section, full radial clearance in the threads across the tap lands, and additional relief in the tap chamfer area. All of these features are used to reduce friction and heat.
- In some cases, larger H limits might be required to overcome the shrinkage.
- Choose a tap made from premium grade materials to prevent heat and wear resistance. Greenfield Tap and Die offers these in our standard product lines.
- TiN+CrC/C surface treatment was developed to improve tapping performance in titanium alloys.
- Lubrication and proper pre-tapped hole size are vital to success. Use a compatible tapping fluid that provides plenty of lubrication to reduce friction.
- Select a drill that will produce the largest hole size allowed by the thread class callout (2B or 3B).
- Due to the additional clearances required, positive feeding of the tap is highly recommended.