Copper

Copper is the industry standard for thermal and electrical conductivity, making it essential for electronics and automotive (EV) applications. However, pure copper (like C10100/C11000) is soft and "gummy," making it difficult to machine without deformation. Jucheng Precision has mastered copper machining strategies using specialized sharp carbide tooling and optimized coolant systems. We utilize our 25 sets of 5-axis CNC machines to produce intricate heat sinks with high aspect ratios that standard 3-axis machines cannot achieve. As an IATF 16949 certified manufacturer, we also supply high-volume, high-precision copper busbars and connectors for the electric vehicle industry, ensuring 100% electrical performance and surface integrity.

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Available Copper Grades

Grade	Common Name	Key Characteristics	Typical Applications
C10100	Oxygen-Free Electronic (OFE)	99.99% pure copper. Highest conductivity rating (101% IACS). No embrittlement.	High-end audio, vacuum interrupters, particle accelerators, superconductor components.
C11000	Electrolytic Tough Pitch (ETP)	99.9% pure. Standard grade for electrical use. Excellent conductivity (100% IACS).	Busbars, wiring, electrical contacts, heat sinks, gaskets.
C14500	Tellurium Copper	Free-machining copper. Contains ~0.5% Tellurium. Machinability rating of 85% (vs 20% for pure copper).	High-volume machined parts, welding torch tips, electrical connectors.
C17200	Beryllium Copper	High strength (comparable to steel) and hardness, non-sparking, non-magnetic. Hazardous dust.	Springs, load cells, oil & gas drilling tools, aerospace bushings.

Copper Machining Capabilities

Capability	Technical Description	Jucheng Advantage
High-Efficiency Milling	Using 5-axis CNC centers to mill complex cooling channels and thin fins on copper heat sinks.	We achieve thin-wall features (down to 0.5mm) without bending the soft copper fins.
EDM Electrode Mfg	Machining high-precision copper electrodes for Die Sinking EDM applications.	Our precision ensures that the electrode shape is perfect, translating to high-quality molds for clients.
Surface Protection	Post-machining Electroless Nickel Plating, Silver Plating, or Passivation.	Prevents copper oxidation (green patina) and ensures long-term solderability and conductivity.
Precision Turning	Turning of electrical contacts, pins, and terminals with smooth surface finishes (Ra 0.4).	Ensures maximum contact area for electrical transmission, critical for high-voltage applications.

Fabrication Guidelines for Copper

Tooling Selection:
Copper is “sticky.” We use highly polished carbide tools with sharp, positive rake angles. This helps shear the metal cleanly rather than pushing it, preventing Built-Up Edge (BUE) which ruins surface finish.

Workholding:
Because copper is ductile and heavy, it can deform under clamping pressure. We use custom soft jaws or vacuum fixtures to hold parts securely without leaving clamp marks or distorting the geometry.

Feeds & Speeds:
We optimize speeds to avoid excessive heat which can make copper “gummy.” Aggressive feed rates are often used to break chips, which otherwise tend to be long and stringy.

Drilling Deep Holes:
Drilling copper requires “peck drilling” cycles to clear long chips. We use high-pressure coolant to flush chips out, preventing them from jamming and breaking the drill.

Primary Application Industries

Automotive & EV (IATF 16949)
Key Parts: High-voltage busbars, battery terminals, charging contacts.
Why Copper: Maximizes efficiency in power transmission and battery charging systems.

Electronics & Semiconductors
Key Parts: CPU heat sinks, cold plates, liquid cooling blocks.
Why Copper: Superior thermal conductivity pulls heat away from sensitive chips faster than aluminum.

Industrial Manufacturing
Key Parts: Welding electrodes, EDM electrodes, power distribution blocks.
Why Copper: High melting point and conductivity make it ideal for transferring energy (welding/sparking).

Aerospace
Key Parts: Heat exchangers, avionics cooling systems.
Why Copper: Reliability in thermal management for mission-critical flight electronics.

Material Properties

Density	8.90 - 8.96 g/cm³
Tensile Strength	200 - 350 MPa
Yield Strength	60 - 300 MPa
Elongation at Break	30 - 50 %
Elastic Modulus	110 - 120 GPa
Hardness	40 - 90 HRB
Thermal Conductivity	350 - 390
Electrical Conductivity	85 - 101 % IACS
Melting Point	1083 °C
Max. Part Size	2000 mm (L) x 800 mm (W) x 600 mm (H)