... drag drill bit for water well drilling 1.ISO9001:2000 2.Wings/Blade: 3, 4 ABOUT USZhengzhou ... like mudstone, shale, sandstone, etc. mainly used for drain hole, grouting hole, geological and hydrology drilling, ... are three wings, while sometime people need for wings, five wings ro six wings.Our ... rates by reducing change over.3. Fast penetrating two wing drill bit for wet drilling with centre flushing ...