What Is Scrap?

Scrap consists of discarded ferrous and non-ferrous metal produced both during the manufacturing process of metal products as well as from the recycling of consumer products.   For over 150 years, the steel industry has been recycling and using scrap to produce steel. Using recycled scrap as raw material in steel production lowers overall costs and is more environmentally friendly.

Mills that consume scrap not only reduce their consumption of new resources but also reduce the amount of greenhouse gas emissions that they produce.  Scrapyards and scrap recycling facilities segregate, sort, and further process scrap materials by grade and by intended use.  Standards for the classification of steel scraps have been developed by the Institute of Scrap Recycling Industry (ISRI).  These standards provide specifications for the classification of steel scrap based on the type, sizing, and metallic and residual composition.

How Can You Identify Scrap Metals?

Understanding how to identify metals for scrap can help you sort different metal types properly and reuse them for the correct purposes. Metals are identified by different traits. You can complete metal identification and sort various types of scrap metals by the following traits:

Color

Some metals have distinctive colors that indicate what types they are. You can identify some metals simply by looking at them. However, it’s important to remember that some metals are painted or rusted, so their appearance may differ from their original, natural color. You can chisel paint or rust off of metal to see its true color and sort it correctly.

Copper-colored metal is usually red brass or copper. Copper is challenging to cast, so molded or cast metal is most likely red brass. Gold-colored metals are different from metal gold. Metal gold is almost the same color as brass, but it is darker and less yellow than brass. If you have gold-colored metals, they are most likely brass because metal gold is rarer than brass.

Magnetism

A metal’s magnetic response can tell you whether it’s ferrous or non-ferrous. Hold a regular magnet to a piece of metal you want to identify. Ferrous metal contains iron and is attracted to magnets, so you can identify it as an iron alloy if the magnet sticks to the metal. Non-ferrous metal is without iron and is not attracted to magnets. If a magnet does not stick to a piece of metal, it is a non-magnetic metal such as brass or aluminum.

Hardness

Some metals are harder than others. You can test a metal’s hardness with a mill file or a cold chisel and hammer.

• Pure copper: Pure copper is a softer metal. If you file a piece of metal with a mill file and it flakes easily, it is most likely pure copper.
• Steel: Steel is harder and flakes less easily than copper.
• Cast iron: If you use a cold chisel and a hammer to test a metal’s hardness and you get brittle flakes that break easily, it is likely cast iron.
• Aluminum, steel and malleable iron: If chiseling a piece of metal gives you continuous, durable flakes that don’t break easily, you most likely have malleable iron, aluminum or steel.

Oxidation

A metal’s oxidation or lack of oxidation reveals details about its chemical makeup and what type of metal it is. A metal’s condition and age can affect its oxidation, so newer and well-maintained metals may not have any oxidation to reveal their identity. To identify metals by oxidation, you can look for the following indicators:

• Green coloring: When copper and bronze metals rust, they develop a green color.
• Red rust: A distinctive red rust color indicates that a piece of metal contains iron.
• No oxidation: Stainless steel and chromium do not oxidize.

Weight

Certain metals are heavier or lighter than others. You can feel a piece of metal’s weight or weigh it on a scale to determine what type it is. Iron and lead are on the heavier side, while aluminum is more lightweight and easy to bend.