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THE VALLEY FORGE.

Forging is probably the most misused term in the industry today. I've had customers actually call me and want their parts made from "forging steel." There is no such thing.

Forging is a process, not a type of material. The process goes like this: a bar of a known alloy is heated to forging temperature, usually above 1,850[degrees] F, and is pounded into a mold to roughly the shape of its final dimension. The two mold halves are actually pounded into each other, with the cherry-hot material in between.

I have made many forging dies in my career for the electrical industry. A sample die might have three cavities. The first would be a very generic rough shape, the second would be a bit closer to the final shape, the third would be near the net shape of the object.

In use, the operator heats a bar of steel to the desired temperature, and holding it with tongs, places it over cavity one. As the machine is tripped into action, the upper half of the mold drops onto the lower half of the mold and squashes the steel in between the two pieces. This may take several hits depending on the complexity of the cavity. Then the steel is reheated, and moved to cavity two, where the process is repeated.

Everyone who has seen an old western movie has seen the blacksmith do some forging, only he used a three pound hammer to form the steel in the shape of a horseshoe.

The process is intended to reduce final machining requirements by getting the material closer to net shape by reforming. For instance, a lug on a 1911 barrel sticks out from the main diameter of the barrel. One could make the barrel from 3/4" diameter steel if not for this lug. However, this lug increases the diameter requirement to 1 5/8" diameter.

If the barrel has this lug forged in place, the steel weight requirement drops over half, and the machining requirement more than doubles. You can see how this one change can reduce the cost of material, and later machining time, if the raw material is forged to begin with.

Smith & Wesson does a lot of forging in their plant. Colt uses forgings for their slides and frames as well. These companies forge their parts closer to net shape to save valuable machining time and steel cost.

A common belief is that if the material is forged, it is somehow stronger. I dispute this "fact." Many steel experts agree that this is not the case. If a known alloy of bar stock has a certain tensile strength, that tensile strength remains the same after forging, assuming of course that all heat treatments are equal.

One does manage to get the grain structure of the steel rearranged and aligned in the raw part with forging, but I'll still argue that this is not a significant advantage when applied to a firearm part.

Only heat treating affects the ultimate tensile strength of a given material, and the only difference between a forging and bar stock is that the forging has been heated bright orange and been pounded into a die at the beginning of its process.

Original government specifications on the 1911, for instance, offered forgings as an alternate method of construction on the slide and barrel. No alternate method was specified for the frame--which, by the way, as late as 1960, was only specified to be made from 1035 low alloy steel. The 4140 alloy and 416 stainless alloys almost everyone uses today are far superior to that specification.

The good news about forgings is that it lowers the cost of your gun, and the delivery dates are better because of the use of forgings. Machining costs and material costs fall drastically when forgings are employed.

The bad news is the initial cost of the forging die, and the quantity of forgings most foundries require the customer to purchase at one time. A full-cycle anneal is required after forging prior to any machining operations being done, because the material heat treats itself by cooling in the surrounding air.

The most important aspect of this discussion of manufacturing methods is the fact that, due to the improvement in steel alloys, almost every part in a modern gun is overbuilt compared to what was available only a few years ago. Overbuilt to the extreme, so that any minor improvement in the use of one process or another is really a moot point.

We have much better quality control, and a better understanding of what it takes to make a good gun. We should all do more to insure that we keep what we have. Get a new shooter involved, and get him into the NRA!
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Author:BROWN, ED
Publication:American Handgunner
Article Type:Brief Article
Geographic Code:1USA
Date:Nov 1, 1999
Words:798
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