Over five decades ago, the industrial company Arconic manufactured a revolutionary 5083 casting alloy—Mic 6. The aim was to meet the rising demands for aluminums with improved flatness, stability, fine grain structure, and tolerance. Though Mic 6 had exceptional dimensional stability, its anodizing properties were subpar. To fill that gap, PCP Aluminium introduced Alca 5 cast tooling plates in the year 2006. These plates featured improved anodizing characteristics without compromising on quality. Today, both Alca 5 and Mic 6 are highly sought-after in the industry for fabricating and tooling precision instruments. When it comes to Alca 5 vs Mic 6, understanding their respective manufacturing processes can help you understand which one makes more sense for your intended application.

How is Alca 5 Manufactured?

Alca 5 is engineered using a vertical DC casting process. This process utilizes virtually porosity-free billets whose structure is maintained even in vacuum and pressure applications. It also gives Alca 5 a slight edge over Mic 6 in terms of strength, elongation, corrosion resistance, anodizing response, painting qualities, and weldability.

DC casting makes use of prime aluminum ingots for the production process. It begins by cutting a very large slab of aluminum into ingots of near net thickness. They are then precision-milled on both sides and saw-cut to an appropriate width and length to remove surface imperfections. The process ends with applying PVC coating to offer protection during transit.

How is Mic 6 Manufactured?

Unlike Alca 5, Mic 6 casting plates are manufactured using a horizontal casting process. Accordingly, structures have porosity and surface defects. Mic 6 plates are casted to near net thickness and the molten metal is purified using various technologies. The process removes entrapped gasses to reduce porosity from the grain structure. The plates then go through a thermal treatment to remove any stress and reach a desired hardness—achieving a final thickness in the process. The end result is a flat and dimensionally stable casting plate.

Both Alca 5 and Mic 6 are available in various gauge sizes (between 1/4″ – 4”) with a thickness tolerance of +/- .005” and a surface finish of 20 RMS or better. However, there are many differences between the two in terms of physical, thermal, and mechanical properties as described below.

Alca 5 vs Mic 6: Major Differences

Anodizing Response

Aluminum with good anodizing properties retains a lustrous exterior and lasts longer thanks to its anti-corrosive properties. But the wide variety of elements that contribute to Mic 6’s machinability make it equally hard to anodize. While Alca 5 is produced using a modified 5083 aluminum alloy to attain a virtually porosity-free microstructure, Mic 6 features a porous microstructure. This makes Alca 5 a better candidate for anodizing than Mic 6.

Cost Savings

The modified 5083 alloy composition of Alca-5 can result in cost savings. For every bit of plate purchased, Alca 5 is going to weigh 5% less than Mic 6. That gives Alca 5 a 5% cost benefit advantage over Mic 6.


For a casting plate, the ability to resist permanent deformation matters. In this regard, the Brinell hardness test can provide useful information. The Brinell hardness of Alca 5 is slightly higher than that of Mic-6 (70 vs 65). These values indicate that Alca 5 has a comparatively better chance of surviving any permanent or plastic deformation when under pressure.


Alca-5 is available in larger widths. PCP has advanced milling lines to precision mil Alca-5 up to 96” wide. But the Mic-6 is available at a maximum width of 60.5”. However, transporting a 98” wide plate is a challenge at a whole new level. You need a responsible metal supplier to get rid of delivery hassles at the least.

Welding Characteristics

The welding characteristics of Alca 5 vs Mic 6 are often the most highlighted aspects of each. Mic 6 plates have poor weldability whereas alca 5 plates don’t. Mic 6 components also include a fair amount of silicon, which is why welding is rarely used in mic 6 casting plates. When welding is necessary, it’s better to opt for MIG instead of TIG to minimize heat input. You’ll also need to ensure the sufficient flow of inert gas and oxidation to avoid cracking.

The table below highlights a few more Alca 5 vs Mic 6 differences that can make choosing the right option easier for you.

Property Mic 6 Alca 5
Typical yield strength 15 ksi 18 ksi
Typical tensile strength 24 ksi 41 ksi
Elongation in 2” 3% 15%
Corrosion resistance Poor Excellent
Thermal conductivity 82 btu/h⋅ft⋅°F 69.3 btu/h⋅ft⋅°F
Modulus of elasticity 10.3 ksi x 103 10.3 ksi x 106

Where to Buy Alca 5, Mic 6, and Other Aluminum Alloys

Industrial Metal Service has been supplying precisely cut aluminum alloys to fabricators and small machine shop owners in the San Francisco Bay Area for more than two decades. Our expansive inventory can meet your metal requirements and includes iron, copper, titanium, steel, and much more. Our high-end metal sawing infrastructure makes quick work of challenging alloys such as aluminum and titanium. And to help you in the most budget-friendly way possible, we also supply verified metal alloys apart from new metals sourced from U.S. mills.

If you’d still like to learn more about Alca 5 vs Mic 6 or can’t decide between the two, give us a call to discuss your project requirements and we’ll gladly help.
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IMS Team

Industrial Metal Service has decades of experience and over 1.1 billion pounds of metal sold and recycled. Our founder, Jeff, has spent his life in the industry and prides himself on offering fair, efficient, trustworthy, knowledgeable, outstanding customer service. We offer metal salesmetal recycling pickup service, and other associated services, such as precise metal sawing, machinery teardown, and warehouse cleanupGive us a call and we’ll get it done.