__________________ indicates the time duration by which we comes to know about the destructive period of an equipment.

In _________ the bits for Jack hammer and drifters are forged on one end of the drill Steel.

__________________ is used in a power or hand drill to form the conical recess for the heads of countersunk screws.

__________________ is used for carrying out the earth work operation of a road.

________________ are Steel bits which are screwed to the ends of drill rods and they can be attached to or removed from …

Due to ___________ the equipment seems physically sound but it becomes old fashioned and the rate of its output becomes …

A _____________ is a mechanism in the shape of a cylinder or drum, over which rope or chain is wound.

__________________ ropes consists of strands of wire of iron, Steel, etc. which are twisted around the core of hemp.