Hammer

Hammer, a tool for beating malleable materials into form or for driving nails, wedges, &c. Often hammers are required of greater weight than a man can wield, and a great variety of power-hammers, masses of iron raised by steam and falling by gravity, are used. The helve or shingling hammer, used for compressing the mass of iron drawn from the puddling furnace, and the tilt-hammer, used in the manufacture of shear-steel, are important examples of such hammers. The first is a heavy bar of cast iron about ten feet long, weighing three or four tons and upwards, to which is attached a head of wrought iron faced with steel, weighing nearly half a ton more. It works upon an axis at the end of the bar farthest from the head, and is raised by cams attached to a heavy wheel set in motion by steam or water power; these cams strike or 'lick' a projection extending beyond the head, and thus raise it about 18 or 20 inches at the rate of from seventy to one hundred times per minute. The tilt-hammer is similar, but much lighter, and is adapted for striking above three hundred blows per minute. In order to attain this velocity a short 'tail' extends with a downward inclination beyond the axis, and the cams strike this downwards, and thus lift the longer arm of the lever to which the head is attached. These, when worked by steam, are, of course, steam-hammers; but when the term steam-hammer is used without qualification, it applies to another and more elaborate machine of very different construction. See STEAM-HAMMER.