Hammers provide a heavy metal head that allows a person to hit or strike wire nails into materials. Mounted at a right angle to the handle, a claw hammer's head features a flat face on one side and a claw on the other. The claw, a split curved wedge, allows bent, misaligned or driven nails to be extracted from materials.

The hammer is measured according to the weight of the hammer's head. The greater the weight, the greater the force required to swing the hammer.