Definition - What does Entry Angle mean?
Entry angle is the angle at which a drill bit enters a pilot hole in a horizontal directional drilling operation. It is one of the design consideration in trenchless construction, along with the exit angle. The typical exit angle is 8 to 16 degrees.
Trenchlesspedia explains Entry Angle
Horizontal directional drilling involves the excavation of a pilot hole, reaming the hole to the appropriate size, and installing pipe through the hole. The line that the drill string follows often includes a steady descent below the earth, then advancement parallel to the ground, followed by a steady incline back to the surface. The angle of the descent from the entrance point of the pilot hole is called the entry angle.
Every horizontal drilling operation is different. Sometimes there are obstacles to be avoided. Modern trenchless equipment and techniques enable workers to complete challenging excavations successfully. Each excavation should be carefully planned in advance. Among the design specifications is the entry angle. An angle that is too steep could cause problems with the final construction.