Mumbai University > Civil Engineering > Sem 8 > Construction Engineering

Marks: 10Marks

Jack hammer is a basic tool of percussion type of rock drill. Jack hammers are hand held, air operated percussion type drills.

A complete jack hammer consists of: hammer, drill steel and Bit.

One end of the jack hammer holds the tool (drill rod with bit) while the other end has the air blower arrangement. Drilling operation includes hammering on the steel as well as turning of the steel in the hole.

The jack hammers are generally used for holes upto 3m depth, though they can be used to drill holes upto 6m deep. The heavier hammers may drill holes upto 6mm in dia.

Drill steels are usually available in lengths of 60cm, 120cm, 180cm and 240gm lengths.

Jack hammers are generally classified according to their weights as follows,

1.Sinkers

1. Leg drills

2. Stoppers

3. Drifters

4. Wagon drills

The use of jack hammer is very popular for blast hole drilling in quarries, mines, rock excavation etc.