Which Copper Grade Is Best for High-Precision Electrical Machining Applications?

Copper grade selection decides two things at once: how well your part conducts and how cleanly it machines. Get the grade wrong, and you fight smear, tool buildup, and rejected dimensions all shift long.

We carry copper round bars and precision-ground bars at our Palos Hills, IL facility, backed by over 30 years in the steel and grinding industry. The grades below cover every common electrical machining scenario, so you can match material to application before you order.

Matching Copper Grade to Your Electrical Machining Job

The core trade-off in copper is simple. Purer grades conduct better but machine harder. Alloyed grades machine cleaner, but give up a small amount of conductivity. Knowing where your application sits on that scale narrows the choice fast.

Our copper line covers six grades, from 99.99% pure oxygen-free copper down to machinability-optimized tellurium and sulfur grades. Each one serves a specific set of electrical and machining conditions, and we can help you confirm the right fit when you submit your quote.

C10100 and C10200: Maximum Purity for Critical Electrical Work

C10100 runs at 99.99% copper and is the standard choice for transformers and semiconductors. C10200 is the practical alternative for electrical conductors and vacuum applications where the same oxygen-free requirement applies.

Both grades are soft and require careful tooling and feed control. If conductivity is the primary spec and your machining process is already dialed in, these grades deliver without compromise.

C11000: The Everyday Electrical Grade

C11000, Electrolytic Tough Pitch copper, sits at approximately 99.90% purity and covers the broadest range of electrical applications. Wiring, bus bars, and plumbing components all run on this grade regularly.

It conducts well and is widely available. For most electrical machining work where purity and conductivity are the main requirements, C11000 is a reliable starting point.

C14500 and C14700: Built for the Machine Shop

C14500 Tellurium Copper is the grade we recommend most often for precision electrical machining. Its high machinability makes it a fit for electrical connectors and switch components where both the machined dimension and the conductivity spec matter.

C14700 Sulfur Copper delivers a similar machinability profile for precision-machined electrical parts. The two grades serve the same purpose, and the choice usually comes down to availability and tooling setup.

C12200: When Corrosion Resistance Enters the Picture

C12200, Deoxidized High Phosphorus copper, is the go-to grade for plumbing, heat exchangers, and refrigeration tubing. The phosphorus addition improves corrosion resistance, making it reliable in fluid-handling and thermal management applications.

If your electrical machining job runs in a wet or corrosive environment, C12200 is worth discussing. Contact us directly, and we can help you confirm whether it fits your specific application requirements.

Request a Quote for Copper Round Bars

We supply copper in standard round bar and precision ground bar forms from our facility in Palos Hills, IL. We also offer straightening, chamfering, and cutting to custom lengths so the material arrives ready for your process. Our copper materials maintain compliance with DFARS, REACH, and RoHS, and most are domestically sourced.

Call us at (708) 400-7217, email sales@precisiongroundmetals.com, or submit a quote request at precisiongroundmetals.com. Our team is available Monday through Friday and Sunday, 7 AM to 5 PM.

FAQs

Which copper grade machines the cleanest for precision electrical parts?

C14500 Tellurium Copper is purpose-built for high machinability. It retains good conductivity and suits electrical connectors and precision-machined electrical parts well.

What separates C10100 from C11000 for electrical work?

C10100 is 99.99% pure oxygen-free copper for transformers and semiconductors. C11000 is approximately 99.90% pure and covers wiring, bus bars, and general electrical work.

Do you supply precision-ground copper bars?

Yes. We carry copper rounds as standard round bar and precision ground bar, giving tighter dimensional accuracy and a smoother surface finish for electrical and electronic applications.

Can your copper bars meet DFARS or RoHS requirements?

Yes. We maintain compliance with DFARS, REACH, and RoHS. Most materials are domestically sourced. Contact us to discuss documentation for your specific project.