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Hammers. I nput. high carbon, heat-treated steel Certain specialty hammers may have heads made of copper, brass, babbet metal, and other materials. Dead-blow hammers have a hollow head filled with small steel shot to give maximum impact with little or no rebound .
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Input • high carbon, heat-treated steel • Certain specialty hammers may have heads made of copper, brass, babbet metal, and other materials. Dead-blow hammers have a hollow head filled with small steel shot to give maximum impact with little or no rebound. • The handles may be made from wood, steel, or a composite material
process • 1 The head is made by a process called hot forging. A length of steel bar is heated to about 2,200-2,350° F (1,200-1,300° C). This may be done with open flame torches or by passing the bar through a high-power electrical induction coil. • 2 The hot bar may then be cut into shorter lengths, called blanks, or it may be fed continuously into a hot forge. The bar or blanks are positioned between two formed cavities, called dies, within the forge. One die is held in a fixed position, and the other is attached to a movable ram. The ram forces the two dies together under great pressure, squeezing the hot steel into the shape of the two cavities. This process is repeated several times using different shaped dies to gradually form the hammer head. The forging process aligns the internal grain structure of the steel and provides much stronger and more durable piece
process • 3 During this process, some of the hot steel squeezes out around the edges of the die cavities to form flash, which must be removed. As a final step the head is placed between two trimming dies, which are forced together to cut off any protruding flash. The head is then cooled, and any rough spots are ground smooth. • 4 In order to prevent chipping and cracking of the hammer head in service, the face, poll, and claws are heat treated to harden them. This is done by heating those • 5 The heads are cleaned with a stream of air containing small steel particles. this process is called shot blasting. The head may then be painted. • 6 The face, poll, claws, and cheeks are polished smooth. This removes the paint in those areas. As part of this operation, the v-shaped slot in the claws is smoothed using an abrasive disc.
process • 7 If the hammer has a wood handle, it is formed on a lathe. A piece of wood is cut to the desired length and secured at each end in the lathe. As the wood spins around the long axis of the handle, a cutting tool moves in and out rapidly to cut the handle profile. The position of the cutting tool is driven by a cam that has the same shape as the finished handle. As the cutting tool moves down the length of the handle, it follows the shape of the cam and cuts the handle to match it. The finished handle is clamped in a holding device and a slot is cut diagonally across the top of the handle. The handle is then sanded to give it a smooth surface. • 8 If the hammer has a steel-core handle, the core is formed by heating a bar of steel, until it becomes plastic, and forcing it through an opening that has the desired cross-sectional shape. This process is called extrusion. If the hammer has a graphite fiber-reinforced core, the core is formed by gathering together a bundle of graphite fibers and pulling them through an opening that has the desired cross-sectional shape while epoxy resin is forced through the opening at the same time. This process is called pultrusion. In either case, the core may then have a protective plastic jacket molded around it.
process • 9 If the hammer has a wood handle, the handle is inserted up through the adze eye of the head. A wood wedge is tapped down into the diagonal slot on the top of the handle to force the two halves outward to press against the head. This provides sufficient friction to hold the head on the handle. The wood wedge is secured in place with two smaller steel wedges driven through it crossways. The handle may then be stenciled with ink or labeled with an adhesive sticker to show the manufacturer, brand name, or other information. 10 If the hammer has a steel or graphite fiber-reinforced core, the handle is inserted up through the adze eye of the head. Liquid epoxy resin is then poured through the top of the hole to bond the handle in place. The handle is placed in a hollow die and a rubber grip is molded around its lower portion. The handle may then be labeled with an adhesive sticker to show the manufacturer, brand name, or other information.
output • Hammer
Feedback Positive feedback Negative feedback Not efficient Slow rate of hammering • Sturdy • High sells • Light • Very reliable
