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Alloying, Casting, Rolling, and Slitting

COINING utilizes a variety of metal working processes to prepare the metal material for the stamping of customer parts. These range from alloying and casting to rolling and slitting processes. Everything is done in-house and the metals that we use are readily available. Our material purchased for the production of our products, in particular for solder preforms, are high-purity raw materials. These include gold, silver, tin, lead, indium, palladium, bismuth, antimony and germanium. This allows COINING to control all aspects of production, quality, and minimizing lead times for material deliveries.

If we need it, we control it; we make it happen, fast & right the first time.


Alloying is a process in which two or more metal elements are melted together in a precise combination to form a specific material, or alloy. Alloys are often preferred over single element metals, particularly for solder preforms, because of their different melting points, specific conductivity attributes or improved thermal expansion values. Alloying is done in either an induction furnace or a casting operation, depending on the alloy. If an induction furnace is used, the alloy is poured into bars or ingots for future use. While the combining of metal elements into an alloy may seem obvious, the process requires close control to avoid contaminates and oxidation.

Alloying Process


Casting re-melts, the alloyed material and converts the alloy while in the liquid state to a cast, strip, or rod. The casting process requires a starting bar for the liquidus metal to cling to; once the starting bar is in place, it slowly draws the liquidus metal through a die to form cast strip or rod with the proper cross-sectional dimensions. The result is a uniform bar or rod ready for subsequent processing.

Casting Process


Rolling reduces the thickness of as-cast strip to the final dimensions required to stamp customer preforms or microstampings. Often, several passes through rolling mills are required to reach the final desired thickness. Metal is fed through the rolling mill at a predetermined temperature, pressure and speed to ensure creating the final desired properties. Precision gauges are used throughout the process to closely monitor strip thickness. Sometimes repeated rolling of the material causes it to become overly hard or brittle. In these instances, the material is annealed to soften it in preparation for subsequent rolling operations.

COINING can roll material to as thin as 0.0003 inch (0.0076 mm).

Rolling Process



Once the rolled strip has reached the specified thickness and hardness, the material is slit to the desired width and cut to the necessary length. As the material runs through the machine, extremely sharp circular blades make the slits. The material is then rolled onto a coil ready for stamping.

Slitting Process