Hammers

Hammers, sometimes casually called persuaders, are used to drive pieces together. Their form ranges from tiny hammers wielded by micro-scale hobbyists to hydraulic devices lifted over building pillars by cranes and operated by entire crews of people. For our discussion, we are going to talk about a few of the most common types of hammers you can expect to encounter.

Types of Hammers

  • Claw Hammer - Commonly referred to as the carpenter’s hammer, the claw hammer is generally used for nailing and pulling nails. The claw hammer is made of very hard steel and should never be struck against another hammer or metal object as the head may fracture and produce metal chips. The tapered slot or “claw” on the back of the hammer head is used to pry nails out using the extra leverage of the handle. An oversized version of the claw hammer is the framing hammer, commonly with a checkered hammer face to help keep each blow on the nail head.
  • Ball-Peen Hammer - There are many variations of the peening hammer (straight-peen, cross-peen, diagonal-peen), but the ball-peen or machinist’s hammer is the most common. This hammer has a flat face used to strike chisels, punches, and other metal tooling and a hemispherical peening face used to work metal and round rivet heads. This is one of the most commonly used hammers when marking metal, prototyping, and working in the laboratory.
  • Brass Hammer - Brass hammers are used in situations where sparks generated when striking an object could pose an explosion hazard. Such situations often arise when working with petroleum, natural gas, or other flammable materials. Brass hammers can also be used on objects that must not be damaged assuming that the brass is the softer material (though mallets are often used for this task as well).
  • Dead Blow Hammer - When working on precision work, the rebound of a hammer is often undesirable as the bounce could result in marring or damage of the part. On such delicate work, the very short duration over which the hammer’s kinetic energy is delivered is also a problem. The dead blow hammer is generally hollow and filled with sand or metal shot (small metal balls). The shot lengthens the time of energy delivery and reduces rebound.
  • Mallet - The mallet is a large faced hammer that is smaller than a sledge and is generally made from rubber, rawhide, or wood. Mallets deliver smaller amounts of energy with a soft and non-damaging face. They are generally used for small adjustments or in the assembly of delicate electromechanical devices such as motors.

Use

Using a hammer just takes practice and careful selection. Choosing the correct style and weight of the hammer can make a large difference to how successful your operation is. Raise the hammer and strike the object with the head of the hammer square to the surface being hit.

Safety Precautions

The largest safety hazard is crushing on fingers or toes. Being careful and practicing aiming the hammer blows will help reduce this risk, but even experienced carpenters and machinists will sometimes miss their mark. Using paper fixtures to hold nails safely away from your fingers when learning may be helpful. There is always the chance of the hammer head or tool being struck fracturing. If this occurs, flying metal fragments could result, so eye protection is essential.