About Corbin Commercial Bullet Swaging Equipment

​The LED-1 Lead Extruder Die Set

The LED-1 Lead Extruder Die Set is used in the 1-1/2 by 12 threaded top plate of the Corbin Hydro-Press. It cannot be used with any hand-operated press because the pressure required is simply to great. Hydraulic power is required.

The kit consists of an extruder die body, which can accept a lead billet of about four inch length by .75 inch diameter, a punch which fits into the press ram using a quick release holder, four die inserts which are used to make any of four standard sizes of lead wire from .185 to .390 inch diameter (if you do not specify the calibers or sizes desired, we normally supply .185, .250, .312 and .365 diameters), and a billet casting set which consists of two four-inch long tubes with honed interior surfaces and a base plug/mount for them. There is also a retaining bushing that screws into the top of the extruder, and holds the die insert against the tremendous extrusion pressures.

The extruder can turn about a pound of lead into wire in one stroke. It is important that the lead be pure, soft lead. Alloys harder than Bhn 5 to 6 will stop the extruder (harder alloys can be extruded using a custom built extruder with a smaller billet diameter. Lubricant must be used on the billet: it reduces the friction so much that it can mean the difference between stalling the ram, and making lead wire flow like a stream of toothpaste flows out of a tube when you step on it!

There are two important warnings about lead extrusion: (1) Never place any part of your body over the top of the extruder, or allow anyone to place their hand or face anywhere near the top of the extruder while it is operating. Under rare circumstances, it may be possible for trapped air to compress in the extruder die and blow out the last piece of lead wire like a shot, which could cause serious injury or death. (2) Always wear leather gloves when handling the extruded wire, as it shoots out quickly and very hot!

The length of lead wire than can be extruded depends on the diameter and length of the billet, compared to the diameter of the final wire produced. You can figure out the length by finding the volume of the original billet (length times cross-sectional area) and then dividing by the cross-sectional area of the final wire product. The cross sectional area is 3.14159 times half the diameter squared, for either the billet or the wire. With a one pound billet, most wire diameters range from several yards for small sizes to several feet for the larger ones. Obviously the pressure goes up as the diameter of wire extruded goes down: you can see that if the diameter extruded was the same as the billet, there would be no pressure (just the weight of the lead billet to lift), and if the extruded wire were infinitely small, there would be infinite pressure required to squeeze it out.

This means that large wire extrudes more easily than small wire: eventually, the press runs out of power to extruder when the wire becomes small enough. To get around this, we can make dies that have more than one hole in them, to reduce the total pressure required. Wires as small as thread, such as .080-inch diameter, can be extruded with a number of holes in the die insert. This fine lead thread can be used for such operations as wrapping fishing lures and making small high pressure gasket seals.

Standard diameters of extruder die inserts kept in stock are: .125, .185, .218, .250, .312, .340, .365, .390. Other sizes can be made to order. Custom shapes can be made, subject to engineering limitations for the strength of the die insert. Four stock dies are included with the extruder at no extra cost.

​The CSU-1 Strip Uncoiler

The CSU-1 Strip Uncoiler is a device for feeding coiled copper or gilding metal strip to the jacket making die head mounted on the ​CHP-1 Hydro-press. It handles up to 100 pound coils easily, feeding them from a rotating three-jaw inside chuck that clamps the strip between two huge metal disks to keep the coil aligned horizontally, and holds the coil from the "eye" or inside hole.

A chain-driven motorized assembly inside the steel pedistal receives signals either from the manual control panel on the side of the pedistal, or from a sensor stand that is positioned halfway between the CSU-1 itself and the rear of the CHP-1 press. Usually a distance of six to ten feet is sufficient for the press, sensor, and uncoiler. The strip passes from the top of the coil, between two adjustable sensors that move vertically on a standard, and into the feed fingers of the automatic jacket maker head.

As the jacket maker takes in the strip, inch at a time, and punches and draws it into the first cup, the strip is slowly pulled tighter until it raises to the position of the top sensor. When the top sensor sees the strip, it turns on the uncoiler motor and silently rolls of a partial turn of strip, which drops the strip to the position of the second sensor. The lower or second sensor, upon seeing the strip, turns off the motor. The feed rate and direction can be controlled by a panel on the CSU-1 pedistal. Thus, two units can be set up, one to feed in strip and one to re-coil the punched scrap strip that comes out the other side of the press.

The price of the CSU-1 is considerably less than the price of most industrial strip handlers on the market, but because the CSU-1 is designed specifically for copper or brass strip of 3/4-inch to 1.5 inch width, in the 50 to 100 pound range, it can be built for the most economical price and yet offer features not found on more general purpose handlers.

​Cannelures