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Sizing, coining and Hobbing of Metal in Manufacturing

Parts of  Malleable iron, forged steel, powdered metals, aluminum and other ductile non ferrous metals are commonly finished to thickness by squeezing an operation called sizing. A special die is needed for almost every job, but each piece can be sized in a fraction of time of machining. Thus, sizing is economical wherever applicable in high production industries.


Sizing Operation

 

Operations like sizing have been called coining, but coining more truly involves the impression and raising of images or characters from a punch and die into a metal. The metal is made to flow, and the designs on opposite sides of a coined piece are not necessarily related as in embossing. Hard money is probably the best known product of coining.

 

Coining Process


Hobbing is a method of making molds for the plastic and die-casting industries. A punch called the hob or hub, is machined from tool steel to the shape of cavity, heated treated for the hardness, and polished. It is then passed into a blank of soft steel to form the mold. A prime advantage of this method is that one hob properly applied can make a number of cavities in one mold or in a series of mold. 


Hobbing Process


check out other cold working processes


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