Rock toolsInclude drill bit,drill rods and other accessories.
Drill rodsIs to transfer percussive impact power from rock drill drifter hammer to drill bits,then crushing rock for drilling blasting.

Bore hole, drill rod length decide the depth of drill hole, and bit diameter decide hole size accordingly. Normally for small hole, integral drill steel, tapered drill rods, shank rods are used. for long hole of tunneling, bench and production drilling, underground, thread drill rods, M-F(male-female) rods, extension rods, drifter rod, hollow drill steels, shoulder drive drilling is necessary.