Question

drilling operation uses which of the following control stystem​

Answer 1

Drilling is a cutting process that uses a drill bit to cut a hole of circular cross-section in solid materials. ... The hammering action can be performed from outside the hole (top-hammer drill) or within the hole (down-the-hole drill, DTH). Drills used for horizontal drilling are called drifter drills.

Answer 2

Answer:

Drilling is a cutting process that uses a drill bit to cut a hole of circular cross-section in solid materials. ... The hammering action can be performed from outside the hole (top-hammer drill) or within the hole (down-the-hole drill, DTH). Drills used for horizontal drilling are called drifter drills.

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