Ferrous or non-ferrous? Here's how to tell the difference between metals

Are you standing on the site with a piece of metal in your hand, wondering: is this ferrous or non-ferrous? You’re not the only one. The distinction between ferrous and non-ferrous metals may seem technical, but in practice, it’s crucial for proper processing, recycling, and valuation. In this blog, Krommenhoek Metals explains how you can tell the difference with a few simple steps.

What are ferrous and non-ferrous metals?

The difference starts with iron. Ferrous metals are all metals in which iron is the main component, such as steel, cast iron, wrought iron, and stainless steel. The name comes from “ferrum,” the Latin word for iron. Non-ferrous metals contain no iron or less than 50% iron. These include copper, aluminum, zinc, lead, tin, and precious metals such as silver and gold.

The magnet test is the most important tool

The fastest way to tell ferrous metals from non-ferrous metals? Grab a magnet. Ferrous metals are magnetic and “stick” to the magnet. Non-ferrous metals do not. It’s the do-it-yourself test that gives you 80% certainty right away.

Please note that, due to their composition, some types of stainless steel exhibit a weak or no magnetic response. The magnet test is therefore an excellent initial check, but if in doubt, you should examine other properties as well.

Key Features at a Glance

Corrosion and Rust Formation

Ferrous metals are more susceptible to rust. That is why steel structures are often coated, galvanized, or painted. Non-ferrous metals are naturally more resistant to corrosion, making them ideal for outdoor applications and humid environments.

Weight and Strength

Ferrous metals are significantly heavier but also extremely strong and durable. This makes them perfect for load-bearing structures, bridges, and machinery. Non-ferrous metals are lighter, which makes them the preferred choice in the aerospace and automotive industries, where weight reduction is essential.

Conductivity and Recyclability

Non-ferrous metals, particularly copper, are excellent conductors of heat and electricity. That is why copper is used in cables and electrical connectors. In addition, non-ferrous metals have a higher residual value when recycled. Ferrous metals are cheaper to purchase, but their value depends mainly on volume and quantity.

Recognition in Practice: The Step-by-Step Guide

What should you do if you come across an unknown piece of metal? Follow this practical step-by-step guide:

1. The magnet test
Does the magnet stick? Then it's probably ferrous. Does it not stick? Then it's non-ferrous.

2. Weight and Feel
Non-ferrous metals often feel lighter. Copper and brass are somewhat heavier than other non-ferrous metals, but still considerably lighter than solid steel.

3. Appearance and Color
Non-ferrous metals often have a distinctive appearance: copper is red-brown, brass is golden-yellow, and aluminum has a matte silver sheen. Ferrous metals typically have a gray or dark surface.

4. Context and Application
Consider where the metal is used. Cables, electrical components, or corrosion-prone applications? It’s likely non-ferrous. A structural component or a machine part? Usually ferrous.

Non-ferrous Metal Prices and Recycling

A frequently asked question concerns price. Non-ferrous metals cost more to purchase, but also yield a higher return when sold back. Furthermore, recycling non-ferrous materials is often less energy-intensive. In the ferrous metals trade, the focus is more on large volumes and tonnages at a lower price per kilogram.

Why This Distinction Is Important

For buyers, metalworkers, and recyclers, the difference between ferrous and non-ferrous metals is crucial. It determines not only the price, but also properties such as corrosion resistance, load-bearing capacity, and electrical conductivity. An incorrect assessment can lead to technical problems, a disappointing residual value, or unnecessarily high costs.

The distinction between ferrous and non-ferrous metals isn’t just a theoretical matter—it’s a practical one that directly affects your bottom line and project results. Start with the magnet test, pay attention to the weight, and consider the application. If you follow these guidelines, you’ll be on the right track in most cases.

Do you still have questions about your metals, or would you like to know the value of your ferrous or non-ferrous materials? Contact Krommenhoek Metals. We’re happy to help with honest advice and competitive prices for all your ferrous and non-ferrous materials.