Material Basics

Copper Specifications: A Guide to Global Standards for Copper and Copper Alloys

5 min read • Updated September 2026

Anyone sourcing, comparing, or documenting copper must first navigate the designation systems that identify each grade. These copper specifications vary by region, each using its own logic of letters, numbers, and suffixes to encode composition, product form, and mechanical condition. This guide explains how the main systems work in Europe, the United States, and Japan, and how they relate to one another when a grade must be cross-referenced.

European Copper Specifications (Euronorm)

In Europe, copper specifications are governed by Euronorm (abbreviated EN), a system harmonized across European countries. Euronorm designates copper grades using a six-character alphanumeric code. The first letter, "C", indicates a copper alloy. The second letter identifies the product form, as follows: B for ingots to be remelted into cast products, C for cast products, F for filler materials used in brazing and welding, M for master alloys, R for refined unwrought copper, S for scrap, W for wrought products, and X for non-standard materials. Three numbers then identify the material, and a final letter identifies the classification of individual copper material groups while extending the capacity of the designation system.

This final letter carries particular weight because it identifies the principal mandatory property of the material. Each material condition is represented by a specific letter: A for elongation, B for spring bending limit, D for as-drawn (without specified mechanical properties), G for grain size, H for hardness (Brinell or Vickers), M for as-manufactured (without specified mechanical properties), R for tensile strength, and Y for 0.2% proof strength.

For castings, the applicable properties depend on the casting process, which is indicated by a suffix: GS for sand casting, GM for permanent mould casting, GZ for centrifugal casting, GC for continuous casting, and GP for pressure die-casting.

Obsolete National Systems Still in Use

Although Euronorm is accepted and applied throughout Europe, copper specifications from older national systems remain common in existing documentation. Designations from the German DIN, British BS, French AFNOR, and Italian UNI still appear in many drawings, standards, and technical documents, and for that reason they continue to matter in day-to-day practice.

United States Copper Specifications and the UNS

In the United States, the most frequently referenced copper specifications are those published by ASTM, SAE, and ASME. To coordinate these different designation systems into a single framework, and to prevent the same number from being assigned to two different metals, the Unified Numbering System (UNS) was established. The UNS is an identification system for commercial alloys, and a key point to understand is that it identifies alloys without providing direct alloy specifications.

In practice, specifications for copper and other alloys frequently refer to the UNS either to identify the grades covered within a document or to cross-reference those grades to UNS numbers. In Total Materia terminology, this category of alloy equivalents is described as "Official".

Japanese Copper Specifications (JIS)

Japanese copper specifications (JIS) are built on ISO standards. Under this system, copper alloys are designated with the optional prefix JIS, followed by the letter C for copper and copper alloys and a four-digit number that reflects the alloying elements.

For example, JIS C1020 contains 99.9% copper, JIS C2720 is a copper-zinc alloy (brass), JIS C5191 is a copper-tin-phosphorus alloy (phosphor bronze), JIS C3601 is a copper-zinc-lead alloy (lead-alloyed brass), JIS C6801 is a copper-zinc-aluminium alloy (brass), and JIS C4430 is a copper-zinc-tin brass.

Explore More in the Copper Series

This article explains the designation systems used to identify copper grades across different regions. The related guides in the Copper series cover the topics you will need alongside it. Copper Grades classifies the metal into its six alloy families, and Copper Properties details the conductivity, corrosion resistance, and strength that those designations ultimately describe. Copper Standards sets out the broader frameworks that govern these designation systems. Together, they connect the designation logic with the grades, properties, and standards behind it.

Frequently Asked Questions (FAQs)

What are the main copper specification systems used internationally?

The principal systems are the European Euronorm (EN), the United States standards published by ASTM, SAE, and ASME (coordinated through the Unified Numbering System), and the Japanese JIS system, which is based on ISO standards. Older national systems such as DIN, BS, AFNOR, and UNI are also still encountered.

How does the European Euronorm system designate copper?

Euronorm uses a six-character alphanumeric code. The first letter "C" denotes copper, the second letter indicates the product form, three digits identify the material, and a final letter identifies the material group and its principal mandatory property.

What does the Unified Numbering System (UNS) do for copper alloys?

The UNS provides a single identification system for commercial alloys in the United States, ensuring that the same number is never assigned to two different metals. It identifies alloys but does not itself provide direct specifications, so documents often cross-reference UNS numbers.

How are copper alloys designated under the Japanese JIS system?

JIS copper alloys use the optional prefix JIS, followed by the letter C and a four-digit number indicating the alloying elements. For example, JIS C1020 is 99.9% copper, while JIS C2720 is a copper-zinc brass.

Are older national copper specifications such as DIN and BS still relevant?

Yes. Although Euronorm is now the harmonized European standard, obsolete national systems such as the German DIN, British BS, French AFNOR, and Italian UNI still appear in many existing documents and remain useful in practice.