COD168-Permanent Concentric Casing System by DTH Hammer

Rock drilling tools factory ProDrill: Permanent Concentric drilling systems by dth hammer which designed to drill and case a hole simultaneously through unstable ground conditions. The driver bit incorporated with a one-time used 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 mini missing the disruption of the surrounding of the drill hole.

Application Range：

It is suitable for drilling water wells, geothermal wells, short micro piles ,medium mini-type grouting hole of building , dam and harbor project .

How to work:

1. Ring bit and casing shoe assembly is welded to casing prior to drilling. Lock the assembly into pilot bit with DTH (Down the Hole) or Top hammer. The pilot bit’s upper shoulder engages the shoulder of the casing shoe.
2. DTH or Top Hammer’s percussive energy is transferred through the pilot and ring bits, crushing rock. Part of impact energy advances casing.
3. On completion of drilling and casing, the drill string with pilot bit is retrieved by a slight reverse rotation to unlock the bayonet coupling. The ring bit stays in the hole, and can be recovered only if the casing is retrieved
4. Drilling continues to the desired depth in the bedrock using a conventional drilling.

Rock Drill Bits Advantages：

Full face head design for faster penetration and straighter hole less torque is required

Can drill in vertical, horizontal or any direction

Minimize disruption to the drilled hole

Varied ring bit diameters to suit different casing requirement

Concentric Casing System by DTH Hammer Technical Data: