Ball-peen hammer - AbsoluteAstronomy.com

A ball-peen hammer, also known as a machinist's hammer, is a type of peening

Peening

Peening is the process of working a metal's surface to improve its material properties, usually by mechanical means such as hammer blows or by blasting with shot . Peening is normally a cold work process...

hammer

Hammer

A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

used in metalworking

Metalworking

Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills,...

. It is distinguished from a point-peen hammer or chisel-peen hammer by having a hemispherical head. Though the process of peening has become rarer in metal fabrication, the ball-peen hammer remains useful for many tasks, such as striking punch

Punch (tool)

A punch is a hard metal rod with a shaped tip at one end and a blunt butt end at the other, which is usually struck by a hammer. Punches are used to drive objects, such as nails, or to form an impression of the tip on a workpiece...

es and chisel

Chisel

A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...

Uses

The original function of the hammer was to peen rivet

Rivet

A rivet is a permanent mechanical fastener. Before being installed a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or pre-drilled hole, and the tail is upset, or bucked A rivet...

ed or welded

Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...

material, which makes it as flexible as the surrounding metal. Today, the ball end of the hammer is used to cut gasket

Gasket

s, expand and shape the free end of copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

roves, light rivets, and "set" rivets (which completes the joint).

Variants

Variants include the straight-peen, diagonal-peen, and cross-peen hammer. These hammers have a wedge-shaped head instead of a ball-shaped head. This wedge shape spreads the metal perpendicular to the edge of the head. The straight-peen hammer has the wedge oriented parallel to the hammer's handle, while the cross-peen hammer's wedge is oriented perpendicular. The diagonal-peen hammer's head, as the name implies, is at a 45° angle from the handle. They are commonly used by blacksmith

Blacksmith

A blacksmith is a person who creates objects from wrought iron or steel by forging the metal; that is, by using tools to hammer, bend, and cut...

s during the forging

Forging

Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons...

process to deliver blows to a forging or strike other forging tool

Tool

A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

Head materials

Ball-peen hammers have two types of heads: hard-faced and soft-faced. The head of a hard-faced hammer is made of heat treated forged

Forging

high-carbon steel or alloy steel; it is harder than the face of a claw hammer

Claw hammer

A claw hammer is a tool primarily used for pounding nails into, or extracting nails from, some other object. Generally, a claw hammer is associated with woodworking but is not limited to use with wood products...

. The soft-faced hammers are made from brass

Brass

Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

, lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

, tightly wound rawhide, or plastic

Plastic

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

. These hammers usually have replaceable heads or faces, because they will deform, wear out, or break over time. They are used to prevent damage to a striking surface, and are graded by the weight of the head.

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.