Always choose the proper tool for the job. Hammers, mallets and other striking tools are among the most common hand tools around; they come in many types and sizes (hammers are sized by weight) depending on the specific design of their use. Some important things to consider when selecting a hammer:

Selection Criteria

Bevel: a bevel allows hammer claws to easily slip under nail heads that are either embedded or just close to the surface. A bevel or chamfer on the striking face will reduce the chance of chipping or damaging the face, making the hammer safer to use.
Handles & Grips: higher quality wooden handles are hickory and ergonomically shaped. Fiberglass and tubular steel hammers should include a vinyl or plastic grip molded to the handle to prevent slipping. Solid steel handles should feature an air-cushioned grip for shock absorption.
Hardness: forged steel heads are best for strength, while heat-treated heads ensure a hammer's durability and wear resistance.

Head Components

Claw: may appear curved or straight depending on the type of hammer selected. A curved-claw hammer will provide greater leverage for removing nails, while a rip or straight claw design is better suited for demolition work.
Eye: should provide a secure head to handle assembly when manufactured separately. Today however, many hammers are forged from one-piece of steel, eliminating any chance for the head to separate from the handle.
Face: typically considered the business end of the tool. Quality hammers will provide a larger striking surface (a.k.a. "face-space") than hammers of equivalent weight for surer strikes and easier, quicker nail driving.
Poll & Neck: absorbs the impact of each strike. Quality hammers incorporate a hot forge, heat treating process to insure exact tempering of the steel to produce a durable, high performance tool.