26. The top and bottom fullers ([Fig. 13]) are made in pairs with convex semicircular projections or working faces, whose diameters should correspond, if intended to be used together. As the former is quite frequently used alone, it may be made of any desired size. The top fuller, like the top swage, is made to be used with a handle; the bottom fuller, fitted to the anvil like a bottom swage, generally is placed for use with the length of its face parallel to the length of the anvil.
They are used together for forming depressions or shoulders on opposite sides of the material; from the shoulders thus formed, the metal may be forged without disturbing them. They are used also for rapidly drawing out metal between shoulders or projections which may have been previously made and are to be left undisturbed. The top fuller is used singly in making scarfs for welding, in forming grooves, in smoothing fillets and semicircular depressions, or in forming shoulders on only one side of metal.
27. The button head set or snap (A, [Fig. 14]) as it is sometimes called, has a hemispherical depression on its face. It is used for making heads of rivets or finishing the heads of bolts. Only a few different sizes are required, unless considerable riveting or bolt making is to be done.
Fig. 14.
A, the button head set; B, the heading tool.
28. The heading tool (B, [Fig. 14]) is used exclusively for forming the heads of bolts or rivets. Formerly a very large assortment of these tools was required in a general shop; but as bolts can now be made so cheaply by modern machinery, there are not many made by hand. It would be advisable to have a few general sizes, however, because they are sometimes convenient in making other forgings, and bolt making affords an instructive exercise.
29. The swage block (A, [Fig. 15]) rests on a cast-iron base B. It is a very useful tool in any smith shop and does away with the necessity of having a large assortment of bottom swages, as only top swages will be required for large-sized material. The block is made of cast iron and of different thicknesses. The depressions on the edges include a graduated series of semicircular grooves that can be used in place of bottom swages; a large segment of a circle, which is handy in bending hoops or bands; graduated grooves for forming hexagonal boltheads or nuts; and sometimes a V-shaped and a right-angled space used for forming forgings.
Fig. 15.—The Swage Block.
The holes through the blocks are round, square, or oblong. The round ones can be used in place of heading tools for large sized bolts, or in breaking off octagon or round steel after it has been nicked with the cold cutter. The square holes may be used either for making and shaping the face of a flatter or a round-edged set hammer, or in place of a heading tool, when a square shoulder is required under the head. They may be used, also, for breaking square steel. The oblong holes are convenient for breaking lathe tool material. Some swage blocks have in addition a hemispherical depression on the side, convenient for forming dippers or melting ladles.