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Tinned Pure Copper Wire

Updated: 2026-07-15

Overview

Tinned pure copper wire consists of a high-purity copper core electroplated with a thin layer of tin. The tin coating provides superior protection against oxidation and corrosion, extending the wire's lifespan in harsh environments. This combination makes it ideal for applications requiring reliable electrical conductivity and durability. Copper's innate conductivity (100% IACS) is preserved while the tin layer enhances solderability, reducing the need for additional flux in assembly processes. The wire is available in various gauges and tin thicknesses to suit specific industrial requirements.

Physical and Chemical Properties

The copper core exhibits a conductivity of 58.5×10⁶ S/m at 20°C, with tin's resistivity (11.5×10⁻⁸ Ω·m) minimally affecting overall performance due to the thin coating. The tin layer typically ranges from 2-5% of the wire's total weight, providing a balance between protection and cost. Chemically, the tin coating forms a passive oxide layer that resists sulfur compounds and moisture, preventing the green corrosion common in bare copper. The wire maintains flexibility (up to 15% elongation for annealed varieties) while withstanding temperatures from -40°C to 105°C continuously.

Main Applications

In electronics manufacturing, tinned copper wire is preferred for PCB interconnects and component leads due to its oxidation-free solder joints. Automotive industries use it for battery cables and sensor wiring where vibration resistance is critical. Marine and offshore applications benefit from its saltwater corrosion resistance, while power transmission employs it for grounding systems and flexible conductors. The telecom sector utilizes fine tinned copper wires in cable shielding to prevent signal interference.

Safety and Storage

While non-hazardous under normal conditions, the wire should be stored in sealed packaging with desiccants to prevent tin whisker formation. Cutting or stripping may produce fine copper/tin particles—use local exhaust ventilation in high-volume processing. For fire safety, tinned copper wire meets UL standards for flame retardancy (typically UL 758 or UL 1581). Avoid contact with strong acids or alkalis that could degrade the tin coating. Shelf life is effectively unlimited when stored properly.

B2B Procurement Guide

Key specifications to verify include: copper purity (99.95%+ for best conductivity), tin coating uniformity (ASTM B33 standards), and temper (soft annealed vs. hard drawn). Diameter tolerances should meet IEC 60228 Class 5 or 6 for precision applications. Bulk buyers should request mill test reports for conductivity and plating adhesion tests. For specialized uses, custom tin alloys (e.g., tin-silver or tin-copper) may be specified. MOQs typically start at 500kg for standard gauges, with lead times of 2-4 weeks for custom orders.

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