The head of a dead blow hammer is filled with a loose material that shifts during the strike. This is how a dead blow hammer reduces rebound and increases strike force during use. Many dead blow hammers are made with a non-sparking head to reduce the risk of sparking in areas where a spark could ignite flammable gasses. The ability of dead blow hammers to reduce rebound reduces user fatigue and risk of hand, wrist and elbow injuries.
There are many different types of dead blow hammers. Handles are available that are made of wood or fiberglass. Heads are available in solid rubber, sealed plastic, metal and cast polyurethane. Models are also available with replaceable head tips so heads that have been damaged with nicks or scratches can be replaced for applications such as woodworking where a smooth finish on the hammer is required to protect the project.
Dead blow hammers are available in many sizes. Head weights range from 1-pound hammers to 10-pound sledge hammers. Handle lengths are available in different lengths depending on the purpose of the hammer. Heads are also available in a variety of diameters.
The shifting sand or shot increases striking force by up to 40 percent. The full force of the strike is transferred to the object, decreasing the shock to the user. The reduction in user fatigue, hand, wrist and elbow stress is ergonomically desirable to reduce repetitive stress injury that, according to the Occupational Safety and Health Administration. costs employers $15 billion per year.
Always wear safety glasses or goggles when working with tools. A dead blow hammer is filled with loose sand or metal shot which, if the head of the hammer breaks during a strike, will spray wildly. It is almost certain that the some of the loose contents of the hammer head will hit your face and eyes.