Bare Eureka (Constantan) Wire – 0.24 mm Diameter (34 SWG), 125 g Reel

This Bare Eureka (Constantan) Wire is supplied on a 125 g reel and manufactured to a 0.24 mm diameter, equivalent to 34 SWG (Standard Wire Gauge). Made from a copper–nickel alloy with a very low temperature coefficient of resistance, this fine‑gauge wire is ideal for precise electrical investigations where stable and predictable resistance is essential. Commonly used for sensitive resistance coils, bridge circuits, and accurate Ohm’s law experiments, it offers excellent performance in both educational and laboratory environments.

Lightweight, easy to wind, and highly consistent, this wire is particularly suitable for delicate or high‑precision setups in school and college physics lessons.

Key Features

• 125 g reel of bare Eureka/Constantan wire
• 0.24 mm diameter (34 SWG)
• Copper–nickel alloy with low temperature coefficient
• Provides very stable, predictable resistance values
• Ideal for fine resistance coils and precision electrical components
• Easy to wind, shape, and integrate into experimental circuits
• Suitable for physics, electronics, and resistance‑based investigations

Ideal for School Science Lessons

Perfect for KS3–KS5 physics, this ultra‑fine Constantan wire supports:

• Constructing high‑precision resistance coils
• Performing Ohm’s law experiments with consistent results
• Comparing resistance changes across different materials and diameters
• Investigating temperature‑resistant conductors
• Building sensitive measurement circuits such as potentiometers and bridges

A dependable, fine‑gauge resistance wire ideal for high‑accuracy electrical investigations in any school physics laboratory.