6 Inch down the Hole Hammer USES compressed air to drive The Hammer located at the bottom of The Hole to work, in order to break the rock volume by impact. The broken cuttings are quickly discharged by mud through the central pipe in the form of reverse circulation, which greatly reduces the phenomenon of repeated crushing. Therefore, this method of drilling with percussive slewing of the DTH hammer has the advantages of fast drilling speed, high drilling efficiency and good drilling quality, especially in the rocks above the middle rock and higher construction efficiency than the conventional drilling method. https://www.speedmadedrill.com/d...own-the-hole-hammer.html