Electrical Constantan Wire 100gm

Quick answer: This 100gm spool of Constantan wire is used in physics laboratories for precision resistance work, thanks to constantan’s near-constant electrical resistance across a wide temperature range — the property that gives the alloy its name.

Description

Constantan is a copper-nickel alloy specifically valued in laboratory settings because its electrical resistance changes very little with temperature, unlike most metals. This makes it the standard choice for winding precision resistance coils, resistance thermometers, and components used in experiments where a stable, predictable resistance value matters more than temperature sensitivity.

Supplied as a 100gm spool, it allows teachers and lab technicians to wind custom-length resistance elements to a required value, and is also commonly used alongside other metals (such as copper) in thermocouple demonstrations, since the copper-constantan junction is a classic thermoelectric pairing.

Specifications

Safety Note

Constantan wire can still carry current and heat up under sufficient load – avoid touching a wound coil while current is flowing, and switch off the supply before changing connections. Use only with low-voltage classroom power supplies.

Why Choose LabEquip

LabEquip supplies physics lab consumables and wire stock to schools and colleges, with a straightforward buying process and a sales team that can confirm exact gauge and specifications before you order. Explore more of our range below:

• LabEquip home page – browse our full lab equipment range
• Nichrome Resistance Wire 100gm – another resistance-alloy wire stock for lab use
• High-Resistance Coil Unit – a fixed-value resistance circuit component

Frequently Asked Questions

Why is constantan used instead of a metal like copper?

Constantan’s resistance stays nearly constant across a range of temperatures, which makes it ideal where a stable, predictable resistance is needed — unlike copper, whose resistance changes more noticeably with temperature.

What is constantan wire commonly used for in physics teaching?

It is widely used for winding precision resistance coils and resistance thermometers, and in copper-constantan thermocouple demonstrations to illustrate the thermoelectric effect.

How much wire do I get with this listing?

This listing supplies a 100 gram spool of constantan wire. The exact gauge/diameter is not specified for this listing; contact our sales team to confirm before ordering.

Can I combine this with copper wire for a thermocouple demonstration?

Yes, a copper-constantan junction is a classic and widely taught thermocouple pairing used to demonstrate the thermoelectric (Seebeck) effect.

Is constantan wire safe to touch while current is flowing?

Treat it like any current-carrying conductor: avoid touching a wound coil while current flows and switch off the supply before making changes.

How should I store the wire spool?

Keep it wound neatly on its spool in a dry location to prevent kinking, tangling or surface corrosion.

Last Updated: September 2026