Boart Longyear

- Rope threads have a low pitch, 12.7 mm and a small angle of profile

- Sizes: 22 mm – 38 mm

- Good wear properties but poor uncoupling capability

- Ideal for single pass or short hole drilling such as underground tunneling applications that require infrequent uncoupling

- Rope thread larger than R32 is not recommended for extension drilling, especially with high powered drills that have high rotational torque as they will be difficult to uncouple

- HM thread or “T” thread has a larger pitch and a larger angle of profile than the Rope thread

- Sizes 38 mm, 45 mm and 51 mm

- Excellent wear properties and good coupling qualities

- It is ideal for extension drilling with multiple steel

- Compatible with heavy high torque rock drills for surface and underground applications

- Similar angle of profile to the HM thread

- Designed for a 60 mm and 70 mm diameter extension steel for use with the new generation high powered rock drills

- Excellent wear resistance and a pitch angle that uncouples easily

- Vital component of the LASEROD™ Straight Hole Drilling System

- Thread is a shoulder drive system (available in bottom drive as well). The shoulders on the pin and box butt together to transmit energy

- Excellent wear properties and good coupling qualities

- This thread is used in extension tube drilling with multiple tube steels

- Compatible with high torque top hammer rock drills for surface and underground applications