by Rebekah Fuller, Editor at IQS
J. R. R. Tolkien used the great art of forging in The Lord of the Rings to harken back to an ancient time in his Middle Earth creation. What wonderfully foreboding imagery – the fictional forging of these legendary rings of supernatural power. Outside of fictional and historical accounts, the blacksmiths of today keep forging alive and well as a superior process for making a wide variety of tools and hardware out of metals and alloys such as aluminum, brass, titanium, stainless steel, carbon steel and nickel.
It’s not by magic that forging has survived and thrived as technology has advanced. The heart of forging has not changed since its origin in ancient Egypt. From the pre-industrial age on into today’s sophisticated forging facilities, the essence of forging remains the same: how it affects the structure of metals. The results are unequaled in any other form of metalworking. Discussing the different types of forging can get very complicated. Putting it more simply: heating the metal until it’s malleable breaks down the originally coarse grain structure, and then “kneading” it between dies elongates the grains and they recrystallize in a new finer granular structure. This traditional hot forging process relies on the plastic deformation of metal, i.e. when it gets soft and bendy. It is then like play-dough in the forger’s hands, ready to be formed into a virtually infinite number of sizes and shapes.
So what does a finer grain mean for the forged metal parts being created? It means all the imperfections unavoidable in a raw bar of metal – low-density areas, microshrinkage and gas porosity – are evened out during forging for the most desirable density, homogeneity and structural integrity. Forging results in highly sound, reliable metal parts, and with all the various competing options available today, capabilities, costs and advantages of each process need to be taken into account.
Let’s take a moment to compare forging to casting. Casting is definitely the less expensive way to go, and could be a good option if your part is not going to be taxed to the limits of durability. The thing about castings, though, is that they can hide defects that would be made evident during forging. Because of the way forging presses and rolls metal, pores are closed and cracks are welded. Casting does not refine metal in this way; therefore, to the naked eye the cast piece might look immaculate, but it could be cracked and porous below the surface. All these blemishes wouldn’t stand a chance during forging as the part is hammered for further refinement.
Forging just might be the best production option if your requirements call for maximum part strength, special sizes or critical performance. This ancient art has just gotten better and better as it has evolved along with the ever-changing technology. Each individual forged part still depends on the creativity of the one forming it, and in this modern era of state-of-the-art equipment, computers and electronic controls, the sky’s the limit – from big, plain shapes to more complex, customized pieces; from weighing a slight pound to many tons; from inches to several feet. Check out all of the forging processes offered today, such as impression or closed die, cold forging, extrusion, open die and seamless rolled ring forging. Smithies throughout history and literature would be proud of how versatile our modern forging has become.