Content

• Steps
• Method 1 of 2: Identify by color
• Method 2 of 2: Other Methods
• Tips

Copper is a simple metal, so all copper objects have roughly the same properties. On the other hand, brass is an alloy of copper, zinc and some other metals. There are hundreds of different combinations, so there is no simple, unambiguous way to identify all types of brass well. However, brass can almost always be distinguished from copper by its color.

Steps

Method 1 of 2: Identify by color

1. 1 Clean metal if necessary. Both brass and copper develop a patina over time, which is usually green, but sometimes some other color.If the bare metal surface is not visible, try the method used for cleaning brass items. This method works well for both metals, but for reliability it is better to use commercially available brass and copper cleaners.
2. 2 View metal under white light. If the metal is well polished, you will be able to see fake colors in reflected light. Examine metal under sunlight or a white fluorescent lamp, but not under a yellow incandescent lamp.
3. 3 Identify the reddish color of copper. Copper is a pure metal, always having a reddish brown hue.
4. 4 Examine the yellow brass. Any alloy containing copper and zinc is called brass. These metals can be contained in different proportions, resulting in different shades. However, the most common brass has a muted yellow or tan (like bronze) color. Brass is widely used in various parts of mechanisms and machines, as well as in the manufacture of screws. In addition, modern Russian coins of 10 and 50 kopecks are made entirely of brass or are covered with it.
   • Some types of brass have a greenish-yellow hue, but this alloy, the so-called tombac, is used only for highly specialized purposes (in jewelry and ammunition).
5. 5 Note that there are red or orange brasses. Many common brasses with at least 85% copper have an orange or reddish tint. These brasses are commonly used in jewelry, decorative fasteners, and water pipes. An orange, yellow, or golden hue indicates that this is brass, not copper. If any brass is made almost entirely of copper, you may have to compare it to a copper pipe or decoration. If you doubt even after such a comparison, then you have either copper or brass with such a high copper content that the difference is insignificant.
6. 6 Identify other types of brass. Brass with a high zinc content is light golden, yellowish white, or even white or gray. Brasses of this type are rare because they are difficult to machine, but can nevertheless be found in jewelry.

Method 2 of 2: Other Methods

1. 1 Hit metal and listen to the sound. Since copper is a fairly soft metal, a muffled, low sound will be heard when struck against it. In a similar experiment conducted back in 1867, the sound of copper was described as “muffled”, while brass made a “ringing ringing sound”. It may not be so easy to grasp this difference without the appropriate experience, but such a skill is useful when collecting antiques or collecting scrap metal.
   • This method is best for inspecting massive, thick metal objects.
2. 2 Take a closer look if there are any special marks on the metal. Brass is marked with special marks, which, as a rule, begin with the letter “L”. If you find markings that start with this letter, then you are most likely brass, not copper. Copper is often unmarked, but if you find a mark, follow these guidelines:
   • In Russia, copper grades start with the letter “M”, followed by numbers, and brass grades, with the letter “L”, followed by letters and numbers.
   • According to the UNS system adopted in North America, brass marking starts with C2, C3 or C4, or is between C83300 and C89999. For copper marking, designations C10100 through C15999 and C80000 – C81399 are used. The last two digits are often omitted.
   • In Europe, both brass and copper markings start with the letter C. Brass markings end with the letters L, M, N, P or R, while copper markings end with the letters A, B, C or D.
   • Older markings may not comply with these rules. According to some old European standards (which were used more recently), the labeling consisted of the designations of the elements, followed by their percentages.According to this marking, everything that contains the symbols Cu and Zn refers to brass.
3. 3 Check how hard the metal is. This test is usually not very useful because brass is not much harder than copper. After some treatments, copper is especially soft, in which case it can be scraped with a 10 or 50 kopeck coin (the surface of which is made of brass), causing scratches. In most cases, however, scratches remain on both copper and brass.
   • Copper bends more easily than brass, but the difference is also small (and difficult to detect without damaging the object).

Tips

• Terms such as “red brass” and “yellow brass” can have particular meanings in certain industries and regions. In this article, they were used solely to indicate color.
• Brass is used for making tools, not copper. The more copper there is in brass, the darker it is, and the lower and more muffled the sound is heard upon impact. Copper is used to make parts of some wind instruments, but it doesn't seem to affect the sound.
• Copper conducts electrical current better than brass, which is why all reddish electrical wires are made of copper.