DIN 20351:2015-08

In underground hardcoal mining, there is a large daily amount of drilling for blast holes and rock bolting while these tasks have grown increasingly more important in terms of the productivity of mining companies. It is crucial for the economic operation of mines that the cavities created artificially at great depths by means of blasting techniques are established and maintained in a securely controllable manner, sufficiently dimensioned and requiring the lowest possible need for stabilisation and expenditure. The anchoring technique used for this purpose and the roadway-driving by means of blasting are based on precise, fast and low-cost drilling works and rendered reasonable by those alone. The wedge-shaped shank connection is used for fluidless rotary drilling with twisted flat-section drill rods. This means a positive coupling with a rough clearance fit used for torque transmission only. The feed force is transmitted via the drill rod end face to the contact surface of the drill bit. The standard has been prepared by Working Committee NA 008-04-01 AA "Gesteinsbohren/Gezähe" ("Rock drilling/Hand tools") of the Standards Committee Mining (FABERG).