Geotechnical Drilling Casing

Geological Casing Tubes
Standard lengths are 3.0m, 1.5m, 1m, and 0.5m. Other lengths are available on request.
Casing tubes are available in DCDMA sizes BW, NW, HW, PW, SW & Chinese standard sizes  and metric sizes 46 -146 mm.

W Series Casing
Flush-jointed casing: each casing tube has a male thread at one end and female thread at the other end. The heavy wall section provides internal and external mating shoulders for the threaded portion to butt-up against, providing twice the contact area of coupled casing and helping to prevent the threads climbing under heavy torque loads. This is by far the most popular type of casing used in geotechnical applications.
X Series Casing
Flush-coupled casing: each casing tube has a box thread at both ends and lengths are connected together by a pin-to-pin coupling. This allows couplings to be replaced when pin threads become worn or damaged. It also means that the casing tube can have a thinner wall than the coupling, allowing the overall weight of casing string to be minimized. This can be important when drilling to greater depths.

Metric Casing Tubes
Metric Casing Tubes are available in diameter range 46mm – 146mm. They are manufactured from thin wall cold drawn steel tubes of a very high mechanical specification. The tubes are flush-jointed with a male thread at one end and a female thread at the other (thread pitch 4 t.p.i).

The casing tubes are designed to be used in conjunction with TT, T2 and T6 series metric core barrels. For example, a T2-86 core barrel will fit inside 101 metric casing, and a T6-101 core barrel will fit inside 116 metric casing, etc.

The clearance between the core barrel and the inside of the casing tube is quite small, reducing the volume of water that is required for flushing, and creating a high up-hole fluid velocity which facilitates efficient removal of rock cuttings from the borehole.

Size