Why Is the Purity of Copper Important for Wires, and How to Check Whether Copper is Pure?

May 19, 2021 | By Paramount

Copper wires have been in demand ever since the electromagnet and telegram were invented in the 1820s. We haven't got enough of them, till now. Copper wires are the quintessential part of an electrical setup, and it's hard to imagine an efficient appliance without some Cu in it. It's interesting to know that almost half of the entire copper production goes into electrical needs. Well, you can credit this to its electrical conductivity (highest amongst non-precious metals), high tensile strength, good ductility, excellent creep characteristics, and ease of installation.

Copper and its alloys are used in power generation, power transmission, telecommunications, electrical circuits, and several appliances. So, it's a given that the copper needs to be of the best quality, and its purity must not be compromised at any cost. Read on to find out why the purity of copper wire is essential.

Pure Copper & its importance

Given copper's competency and extremely favorable characteristics, it's a metal of choice. No matter however promising properties a metal offers, when it comes to electrical setups, one needs to be extremely considerate that the wire is providing maximum safety and efficiency. Pure copper or electrolytic copper is the one prepared by electrolysis. It's the highest grade of copper (more than 99.95%) and mostly used in making copper wires. This purity delivers maximum conductivity, and even the slightest degradation in purity can hinder the conductivity.

A 0.05% of arsenic impurity in copper can hamper about 15% of its conductivity. That's why Paramount Cables use the best-in-grade copper to manufacture the best quality wires and cables. Pure copper provides exceptional thermal and electrical support to wire and comes with ease of fabrication and great strength.

Okay, but how do I check purity?

Checking copper wire's purity is important for obvious reasons. If the appliance is performing badly or there's some issue with the output even when you've used a pure copper' wire, then maybe you need to get it checked. You can use different testing methods to determine the purity of copper wire. 


For the starters, check for certification that the wires come with. If it's ISO certified, it speaks volumes about the product. There can be an SGS BV certificate or an ISO 9001: 2000 TS16949 certificate - verify any kind of certificate that comes with it.

Magnetism test

Pure copper is not much magnetic and, when objected to a magnetism test, must demonstrate low magnetic properties. When you hold a magnet against pure copper, it shouldn't attract it (given the magnet isn't too powerful.)

Resistance & conductivity

Copper has a resistance of 1.7 x 10^-8 ohm-meters at room temperature, which is why it has excellent electrical conductivity. You already know that pure copper will not be able to conduct electricity efficiently, so you just need to determine the resistivity of the wire and the copper and compare them. If the wire exhibits higher resistivity than that of copper, then there is something unwanted alloyed in the copper.


Density test is one of the most reliable methods - check if the density of the purchased material is correct. The density of copper is 8.92 grams per milliliter. After checking the density, if there's a discrepancy in the value, there must be some impurity in the pure copper you're unaware of.

Before you buy..

Although you can always rest assured about the quality of wires and cables when you get them from Paramount Cables, there are certain quick quality check measures you can take before you buy the wire. Bend the wire to check its flexibility - better the copper, more the flexibility. Check that the centre of the wire is well-aligned and proportionate to all corners - the more defined the centre is, the better the insulation gets. Peel off the PVC coating (inspect the PVC as well) and check whether the wire has twists on it - good quality wires come twisted as it increases its conductivity. Now, you're all set to get your home power-packed with the help of pure copper!