A cold chisel is a heavy duty type of chisel which is designed primarily for masonry work.

Cold chisels are ideally suited to removing mortar from bricks, or tapping though cement blocks and hollow terracotta bricks when making an opening.

Cold chisels are designed to be used with a heavyweight metal hammer to provide a strong striking blow. Over time the head of the cold chisel will mushroom out due to the repeated hammer blows - this is not a problem, just a sign of a well used cold chisel!