Here, too, the depth of the slice must be extremely precise since too deep a cut would substantially reduce the hook's strength. Toolmakers create forms to the size and shape of individual hook styles, and must make a form for each hook size within a style. These resulting dies exactly match the inside radius of the hook shape desired. With the wire point and barb firmly held in position, the wire is then forced to wrap, or bend, around the selected die. The die configuration determines whether the shape is a Sproat, Kirby, Limerick, etc.
Forging is a term applied to a process of forming metal.
In hookmaking it refers to the flattening of the round wire in such a manner as to increase its strength in one plane, or direction. Commonly, hooks are forged on both sides beginning at a point behind the barb, and extending throughout the bend up to the hook shank. Often the forging will include much of the hook shank as well. By flattening both sides of the hook, the strength along a theoretical straight line of pull is increased. The process of forging is accomplished by simply placing individual hooks into a press which flattens the round wire to a controlled thickness.