Contact Us

       TEL : +86-592-5601702  5682036


       Address: Unit 8001, Part A, Minnan Culture Town, 

       No.350, Changle Road, Huli, Xiamen China.361006


Symmetric Overburden Casing Drilling System

Symmetric Overburden Casing Drilling System

The symmetric drilling system is designed to drill and case a hole simultaneously through unstabled ground conditions. The driver bit incorporated with a satisficial ring or reusable ring makes a full face head design which significantly improves the penetration rate and hole straightness of drilling. The internal flushing grooves together with the built-in casing shoes gives a good seal to the button of the drilling hole, and thus minimising the disruption of the surronding of the drill hole.

Symmetric overburden casing drilling system

A pilot bit with large internal flushing holes and external flushing grooves.

Symmetrical ring bit (reamer) with internal bayonet coupling

Casing shoe for driving of casing.

The pilot bit is attached to any common DTH hammer shank or top hammer rod thread.

The casing shoe is welded to the casing. The pilot bit and ring bit are locked together by the bayonet coupling.


They drill a hole large enough to allow the casing to be pulled into the hole. The pilot bit and ring bit rotate with the drill string while the casing shoe and casing do not rotate.


When required depth is reached, the pilot bit is unlocked by a slight reverse rotation of the drill string.


The drill string and pilot bit will be retrieved through the casing, the ring bits and casing shoe will be left in the hole for permanent casing system.


Also the ring bits and casing can be retrievable through the special design for ring bits and casing shoe.

Hot Tags: symmetric overburden casing drilling system, China, manufacturers, suppliers, factory, customized, best, high-quality, CE certification