In the shipbuilding industry, aluminum alloys are increasingly replacing traditional steel due to their lightweight, corrosion resistance, and ease of processing, making them a key material for modern hulls, outfittings, and marine equipment.
Among them, 6061 and 6063 aluminum alloys, both typical representatives of the 6-series (Al-Mg-Si) heat-treatable alloys, are widely applied in the marine sector thanks to their mechanical strength and weldability. However, while they share similarities, they also present important differences.

Introduction to 6-series Marine Aluminum Alloys

6061 Marine Aluminum

6061 alloy belongs to the Al-Mg-Si-Cu series. After heat treatment (T6 temper), it demonstrates excellent mechanical properties and workability, making it the preferred material for critical ship components.
Its advantages lie in high strength, strong impact resistance, and superior seawater corrosion resistance, perfectly meeting the demands of heavy loads and harsh marine conditions.

We supply 6061 aluminum plates, extrusions, and forgings in the T6 temper, tailored to meet high-strength structural needs, along with welding process guidance to ensure installation reliability.

6063 Marine Aluminum

Unlike 6061, 6063 alloy belongs to the Al-Mg-Si series without copper, with properties leaning toward excellent formability, smooth surface finish, and superior lightweight performance. It is more suitable for ship decorative parts, functional components, and low-load structures, enhancing both aesthetics and weight reduction of vessels.

For 6063 alloy, we offer customized extrusion profiles with complex cross-sections, supporting multiple surface finishes and colors, ideal for personalized ship interior and functional component designs.

Comparison: 6061 vs 6063 Marine Aluminum

1. Main Features & Applications

6061: Known for its strength, offering a well-balanced combination of strength, corrosion resistance, and machinability. Often referred to as a “general-purpose alloy,” it is widely used in hulls, masts, large decks, and load-bearing frames that require high stress resistance.

6063: Famous for its extrudability and smooth finish. With lower strength, it is better suited for decorative and functional applications, such as window frames, door frames, interior trims, and railings.

2. Strength

6061: Higher yield strength and tensile strength, making it the stronger of the two alloys.

6063: Lower strength, unsuitable for heavy load-bearing structures.

3. Workability

6061: Good weldability with minimal strength loss after welding. However, slower extrusion speed and more limited ability to form complex profiles, with surface finish being average.

6063: Outstanding extrusion performance, capable of forming complex shapes quickly and cost-effectively. Excellent surface finish, especially suitable for anodizing.

4. Corrosion Resistance

Both 6061 and 6063 offer good corrosion resistance in marine environments.

6061: Performs even better after anodizing or protective treatments, suitable for long-term exposure to harsh conditions.

6063: Reliable corrosion resistance but best applied in interior or less demanding environments.

Shipbuilding: How to Choose?

In shipbuilding, 6061 and 6063 often complement each other. 6061 focuses on the strength and reliability of core structures, while 6063 focuses on the lightweighting and aesthetics of decorative and functional components. The combination of the two optimizes and upgrades the overall performance of a ship.

Both 6061 and 6063 aluminum alloys comply with the environmental and safety standards of the International Maritime Organization (IMO) and the shipbuilding industry in various countries. They contain no heavy metals or other hazardous substances and are 100% recyclable, aligning with the current trend of "green manufacturing and a circular economy" in the shipbuilding industry.