The one yen coin is a readily recognizable item used by Japanese residents on a daily basis.
Official one yen coins produced by the Japan Mint are 100% pure aluminum. The alloy produced by adding various elements is called aluminum alloy.

Aluminum is actively used in a broad array of fields ranging from beverage cans to automobile parts. The addition of elements to pure aluminum produces the various characteristics needed by each of these fields.
Aluminum is steadily being adopted in cutting-edge fields through the addition of new functionality to its familiar conventional characteristics amidst modern-day demand for more diverse and advanced materials.

Characteristics of Aluminum

• Lightweight

  Aluminum is 1/3 the specific gravity of iron. This lightness is being effectively utilized to boost the operating efficiency of sliding and rotating parts, reduce product weight, and enhance products in a variety of ways.

• Strong

  Has great specific strength. Recently discovered high tensile alloy is gathering attention as a material for aircraft and large-scale structures.

• Corrosion Resistant

  Reacts with air, naturally generating a dense, stable oxide film that protects the surface from corrosion.

• Good
  Workability

  Suitable for plastic working. Easily workable into thin, complex shapes that can be additionally processed with relative ease.

• Good
  Electrical Conductivity

  Only 60% the electrical conductivity of copper but 1/3 the specific density, so can pass twice the current as the same weight of copper. Increasing demand in the electronics field.

• Not
  Magnetic

  Nonmagnetic material unaffected by magnetic fields. Utilized for a wide array of applications including medical electronic devices, mechatronics equipment and linear motor cars.

• GoodThermal Conductivity

  Approximately 1/3 the thermal conductivity of iron. Good thermal conductivity also means rapid cooling, a property facilitating use in various areas such as air conditioners, engine parts, heat exchangers, radiating fins, heat sinks.

• Resistant to Low Temperatures

  Characterized by high toughness and resistance to brittle fractures even in extremely low temperatures. These characteristics are attracting attention in cutting-edge fields such as aerospace development, biotechnology, and cryogenically cooled superconductors.

• Reflects
  Light and Heat

  Well polished aluminum reflects infra-red radiation, electromagnetic waves, and a full range of heat rays. Widely used in electronics after mirror finishing is used to enhance its reflective properties.

• Nonpoisonous

  Harmless, odorless and hygienic. Doesn’t damage health or environment like heavy metals. Utilized for these characteristics in fields such as food, pharmaceutical packaging, beverage cans, and medical devices.

• Easy to Cast

  Characteristics such as a low melting point, generation of protective oxide film on the surface even when melted, minimal gas absorption, and good fluidity make it ideal for thin and complexly shaped castings.

• Easy to Join

  Can easily gain a highly reliable joint via welding, brazing, soldering, electric resistance welding, riveted joint, adhesion and various other methods. Efficiently streamlines design and application processes.

• GoodVacuum Properties

  The metal itself has an extremely low gas evolution rate when used in vacuum equipment, and exhibits superb vacuum-reaching performance compared to other materials.

• Easily
  Recycled

  Can be easily melted and recycled due to its low melting point. The energy needed to create secondary metal is a mere 3% of that needed to make primary metal. It can be regarded as an economic material.

• Aesthetically Pleasing

  Aesthetically pleasing even as bare metal, aluminum can be colorfully coated via surface treatment, making it ideal for fields demanding a high level of designability.

Reason for Surface Treatment

We are surrounded by a multitude of metal products in our everyday lives, the majority of which have been surface treated in one way or another to compensate for the various disadvantages of metal.

The use of metal will inevitably lead to corrosion. Disadvantages such as wear, lack of color and no lubrication cannot be avoided. Humans have sought and will continue to seek out new treatment techniques to overcome these inherent disadvantages.