DTH hammer 3 inch

  DTH hammer 3inch

Product description:

The ROSCHEN 3” hammer is designed around proven technology to perform at the top end of the performance scale compared to other tools on the market. These tools are excellent for all types of drilling applications including residential geothermal, production quarry drilling, seismic drilling and small construction drilling.

The optimum range of hole size for blast hole drilling with DTH is 90 mm to 254 mm (3 ½”–10″). Smaller blast holes are generally drilled using top hammer, and larger holes generally use rotary machines.

In other applications, like foundation drilling, DTH hammers can be used with single bit in hole sizes up to . 750 mm (30″). With multiple hammer units CD (Cluster drills) drill holes up to 70″ or 1778 mm.

As a rule of thumb, the smallest hole diameter a DTH hammer can drill is its nominal size. A 4 inch hammer will drill a 4 inch (102 mm) hole. The limiting factor is the outside diameter of the hammer, because, as hole diameter reduces, airflow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 1 inch, so for a 4 inch hammer the maximum hole size is 5 inch (127–130 mm).

Choosing the right hammer is largely determined by hole size and type of rock formation. Ideally, the size of the hammer should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacuate the hole.