Copper Supply & Machining in South Bend, IN

C101 and C110 are both high-conductivity coppers, but they differ in purity and oxygen content. C101, oxygen-free electronic (OFE) copper, is at least 99.99 percent copper with the oxygen removed during processing. Removing the oxygen prevents hydrogen embrittlement, which can occur when copper containing oxygen is heated in a hydrogen or reducing atmosphere during brazing or welding, so C101 is specified for high-reliability electronics, vacuum applications, high-frequency work, and any part that will be brazed in a reducing atmosphere. C110, electrolytic tough pitch (ETP) copper, is at least 99.9 percent copper and contains a small amount of oxygen as cuprous oxide. It is the most common and economical commercial copper, with conductivity near 100 percent IACS, and it covers the vast majority of busbar, grounding, and general electrical applications where the small oxygen content poses no problem. The practical rule is to use C110 for general electrical and thermal work, and reserve C101 for applications that demand the highest purity or that involve brazing or welding in reducing atmospheres where oxygen content would cause embrittlement.

Pure copper grades like C101 and C110 are soft, ductile, and gummy, which makes them difficult to machine cleanly; the material tends to smear and form built-up edge rather than break into clean chips, leading to poor surface finish, tool drag, and stringy chips that complicate production. Tellurium copper, designated C145, solves this by adding a small amount of tellurium, typically around half a percent, which forms a finely dispersed phase that acts as a chip-breaker and lubricant during cutting. The result is dramatically improved machinability, often comparable to free-machining brass, with clean chip formation, better surface finishes, faster cutting speeds, and longer tool life. Crucially, this machinability improvement comes with only a modest conductivity penalty, since tellurium copper retains roughly 90 percent of pure copper's electrical conductivity. That tradeoff makes it the preferred choice for connectors, terminals, electrical contacts, and any copper part with tight machined tolerances or complex features that would be slow and costly to produce in pure copper. When a design needs both good conductivity and efficient machining, tellurium copper is usually the right specification.

Copper parts in electrical assemblies are commonly plated and joined to improve performance and reliability. Plating serves two purposes: protecting the copper surface from oxidation, which can increase contact resistance over time, and tailoring the surface for the application. Tin plating is widely used on busbars and terminals because it resists oxidation while preserving good conductivity and solderability. Silver plating is applied to high-performance contacts where the lowest possible contact resistance is required, and nickel plating provides a harder, more durable barrier, often as an underplate. For joining, brazing and soldering are the standard methods for electrical connections, with silver brazing used where higher joint strength or temperature capability is needed. When brazing copper, the grade matters: oxygen-free C101 avoids the hydrogen embrittlement risk that oxygen-bearing C110 can face in reducing atmospheres. Because plating and brazing are typically outsourced to specialized lines, confirm the specification, thickness, and standard early in the sourcing process, since these steps affect both the electrical performance of the finished part and the overall lead time. Always match the surface treatment to the contact's service environment and electrical requirements.

Yes, copper demand on vehicle programs has grown substantially as electrification spreads, and that trend reaches the South Bend area given its automotive and heavy-equipment manufacturing base. Electric and hybrid powertrains use far more copper than conventional vehicles because of the wiring, motor windings, power-distribution busbars, battery-connection hardware, and charging components they require. Even on conventional and tactical vehicles, the growth of onboard electronics and power-distribution systems increases copper content. For regional shops and buyers, this means more demand for machined and fabricated copper parts such as busbars, terminals, grounding hardware, and connectors, often in tellurium copper for the machined contact pieces and C110 for the conductor sections. The practical implication is that sourcing partners with copper machining and plating experience become more valuable, and that designers should consider the conductivity-versus-machinability tradeoff carefully on each part. While South Bend's strongest material heritage remains steel and aluminum for structural vehicle work, copper is an increasingly important secondary material as power and electrical content rises across both automotive and heavy-equipment platforms.