ISO/TS 16949:2009

03 Technology. Stronger, enhanced design freedom, smother surfaces. Precision, durability and low cost are paramount requirements. Our products are highly valued by the domestic and international automotive industry, because we concentrate on gravity casting in order to meet the toughest specifications.

Our Aluminum Casting Process 1. Gravity Die Casting

We are specialized in gravity casting. At this process, the aluminum melt is poured into the mold by gravity (unlike pressure die casting). Parts that feature complex shapes and have tough mechanical specifications, e.g. for pressure resistance, can be made with this technology. Gravity casting is the ideal casting process for important car parts, such as turbo charger components or housings of fuel injection pumps.

Our Aluminum Casting Process 2. Low Pressure Die Casting

Automotive components with thick walls for high strength can be manufactured using this technology. By applying low pressure, aluminum melt is injected slowly into the mold from below. By applying the injection pressure until the aluminum solidifies, High quality parts can be produced with fewer blowholes.

Our Aluminum Casting Process 3. H-Process (Horizontal Controlled Flow Pouring Process)

The H-Process combines high dimensional accuracy and supreme mechanical properties of gravity casting with the low cost level of pressure die casting. A large number of parts can be produced in one pouring. Therefore, cost reductions can be achieved for automotive parts, such as turbo charger compressor housings, without compromising on quality.
Only NAIGAI masters this special aluminum casting process. The production development was supported by Japan’s Ministry of Economy, Trade and Industry (METI) and classified as a "strategic technology advancement support project".

Our Aluminum Casting Process 4. Sand Casting

In addition to gravity die casting we can also produce sand castings.
As the manufacturing of a mold requires a relatively high investment sand casting is an alternative for small volume production.
At the same time we use sand casting of prototypes before preparing our molds, during the development stage.
This assures the high quality at the time of SOP.

Heat Treatment

Heat treatment is an important process to increase the strength and hardness of castings,
It is indispensable for quality improvement.
We have T6 and T5 heat treatment furnaces, 2 of each.


Machining of the castings can be done in-house. We are equipped with machining centers and NC lathes. By performing all processes from casting to machining in a “total manufacturing approach”, we can assure our excellent quality.