A modern day hammer is a tool consisting of a weighted “head” fixed to a long handle that is swung to deliver an impact to a small area of an object. … The claw hammer has a “claw” to pull nails out of wood, and is commonly found in an inventory of household tools.

Hammers are classified by the weight of the head and the length of the handle. The common curved claw hammer has a 7-20 oz (0.2-0.6 kg) head and a 12-13 in (30.5-33.0 cm) handle. A framing hammer, which normally drives much larger nails, has a 16-28 oz (0.5-0.8 kg) head and a 12-18 in (30.5-45.5 cm) handle.