Copper Machining & Fabrication Suppliers in Wichita, KS

For most electrical work, C110 electrolytic tough pitch copper is the default because of its excellent conductivity, around 100 percent IACS, and its wide availability in bar, plate, and sheet for bus bars and straps. Choose C101 oxygen-free copper when the part will be brazed or used in a vacuum or hydrogen environment, because oxygen-bearing ETP copper can suffer hydrogen embrittlement during those processes. When a part has tight machined features, consider tellurium copper C145, which machines far more cleanly than gummy C110 at only a modest conductivity tradeoff, saving real grief on complex machined components. Temper matters too: soft annealed copper forms and bends easily for grounding straps and shaped bus bars, while harder tempers hold rigid bar geometry. Specify the grade, temper, and the required conductivity rating explicitly on the purchase order, because conductivity is the property the part exists to deliver and the stock counter will not infer your intent from the application alone.

Bare copper oxidizes in air, and copper oxide is far less conductive than copper, so an unplated electrical contact or bus bar joint develops increasing contact resistance over time, which means heat at the joint and potential failure. Plating preserves a low-resistance surface. Tin plating is common for general electrical contact and corrosion protection and is cost-effective. Silver plating is specified where the lowest contact resistance matters, such as high-current connections or high-frequency applications, because silver oxide remains conductive. To verify, require the plating certification stating the plating type and thickness, because an under-plated joint can run hot and fail in service while looking fine on arrival. Settle the plating requirement before the part is made rather than as an afterthought, and for critical connections confirm the supplier can document plating thickness at the contact surfaces. For aerospace bonding hardware, you may also need documented bonding or contact-resistance test results, so confirm the shop can perform and record those electrical measurements.

Copper is deceptively difficult because it is soft and gummy rather than hard. Pure copper grades like C110 tend to smear, tear, and build up on tool edges rather than cutting cleanly, which makes a good surface finish and tight tolerances harder to achieve than the soft material would suggest. This affects supplier choice in two ways. For machined copper components with real tolerances, you want a shop that understands copper's behavior and uses sharp tooling, the right rake angles, and appropriate speeds to avoid tearing, or you specify a free-machining grade like tellurium copper C145 that cuts cleanly. For fabricated copper parts like bus bars and straps, the work is shearing, punching, bending, and plating rather than precision machining, so a fabricator with those capabilities and good plating relationships is the better fit than a precision machine shop. Match the supplier type to whether your part is machined or fabricated, and name the grade so the shop can plan for copper's particular behavior.

The most important and most overlooked document is the mill certification confirming both the copper grade and its conductivity rating in percent IACS, because conductivity is the entire reason the part is copper rather than a cheaper metal. Require that cert, and for the grade itself confirm it matches what you specified, since C110, C101, and tellurium copper are not interchangeable for every use. If the part is plated, require the plating certificate stating type and thickness, as plating thickness directly affects joint resistance and longevity. For brazed or welded copper assemblies, get confirmation that the correct filler and process were used and that joints are sound, because a porous or cold joint in a current-carrying part becomes a hot spot. For aerospace bonding and grounding hardware, the part may carry an AS9100 quality requirement plus specified resistance or bonding-resistance tests, so confirm the shop can perform and document those electrical measurements. The pattern is that copper documentation centers on electrical performance, not just dimensions.