Symmetric Casing System Casing O.D. 273mm

Symmetric/Centrex/Symmitrix Drilling System 
Symmetric is a concentric drilling system with retrievable pilot bits. 

Permanent Model 
The ring bit will be left in the hole after drilling finished. 

This system drills in any direction and in any type of ground condition. 

It is, in fact, the most flexible and efficient overburden system on the markettoday. 

The Symmetric components are made up of: 
---A pilot bits with large internal flushing holes and external flushinggrooves 
---Symmetrical ring bit (reamer) with internal bayonet coupling 
---Casing shoe for driving of casing. 
The Pilot bits is attached to any common DTH hammer shank. 

The Prodemo 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.

Advantages: 
Full face head desigh for faster penetration and straighter hole 
Less torque is required 
Can drilll in vertical, horizotal or any direction 
Minimize disruption to the drilled hole