Horizontal Hole Openers, also known as HDD Reamers, are used to enlarge the pilot hole in Horizontal Directional Drilling(HDD) - HDD is used when trenching and excavating is not practical. This drilling technology allows for a steerable trenchless way to drill underground.

Cutter can be divided into MT type used in soft formation and TCI type used in hard formation. Hole opener takes its advantages in its better teeth distribution, wearing resistance ability, bigger cutting area and higher efficiency.

Assembly bit is made for customers' specific needs. The size is from 500mm-3000mm. It is used to enlarge a hole or connected with a bit on front end to drill pilot hole and enlarge hole simultaneously.