1. Suitable to drill with casing tubes whose outer diameters are from 108mm to 323mm.

2. With stable and reliable working performance and less vibration of drill rigs, they enable to bore holes in rock formations where contain some ovals, boulders and fractures.

3. Application:
Anchoring project, road construction, pipe and cable laying, sampling, geothermal well, water well, piling and etc.