MIC-6 and 6061 are two of the most widely used aluminum alloys. MIC-6 aluminum is designed for dimensional stability, surface finish, and precision machining. 6061 aluminum is often selected for its versatility, weldability, and corrosion resistance. When you’re evaluating the pros and cons of using MIC-6 aluminum vs. 6061 aluminum for a component machining or a fabrication project, it’s useful to understand the properties, characteristics, and typical applications for each of these aluminum alloys.

MIC-6 Aluminum: Properties & Characteristics

MIC-6 aluminum was developed in response to the demand for aluminum plate requests to incorporate stability and tolerance improvements from what was on the market in the 1960s. Its continuous cast process is patented as it produces an aluminum alloy plate that is stable and immune to virtually all distortion during machining and temperature changes it may be subject to once it’s placed in use.  

MIC-6 aluminum is preferred for machining applications that require precise control of tolerances and dimensions. It produces small uniform chips, even with high-speed machining operations, with minimal risk of plate distortion. MIC-6 is often the alloy of choice for manufacturing parts, components, and equipment used for precision measurement.

Tooling & Measurement	Component Manufacturing
Automotive and aircraft tooling Base plates Jigs Gauges Index tables  Routing tables	Chip printers Circuit printers  Dielectrics Medical instrumentation  Robotics  Semiconductor holding trays

MIC-6 is weldable, but you’ll need to be extremely careful to avoid corrosion cracking. The MIG method is preferred to TIG as it minimizes the heat input. For more reliable weldability 6061 aluminum may be the best choice, depending on your needs.

6061 Aluminum: Properties & Characteristics

6061 aluminum is a precipitation-hardened alloy containing magnesium and silicon and is flat-rolled or extruded to produce, plate, bar stock, and round stock. 6061 aluminum is one of the most commonly-used heat-treatable aluminum alloys. Lightweight, strong, and corrosion-resistant even when the surface has been abraded, 6061 aluminum is very workable—easily cut, drilled, formed, tapped, and stamped, with excellent welding qualities. However, compared to MIC-6 aluminum, 6061 doesn’t lend itself as well to precision machining. 

The weight-to-strength ratio, corrosion resistance, and weldability make 6061 aluminum the choice for a broad range of manufacturing and fabrication applications that require high-strength, corrosion resistance, and/or welding.

Aviation & Marine	Transportation
aircraft structures  model aircraft components  yacht structures and components utility boats docks and gangways	truck bodies and frames automobile frames  wheels pistons  railway car components
Sporting Equipment	Manufacturing
bicycle frames and components  fly fishing reels  firearm sound suppressors  SCUBA tanks	base plates jigs machine parts high-pressure gas storage cylinders

Understanding the Differences: MIC-6 Aluminum vs. 6061 Aluminum

The table below provides a quick comparison of the major differences between MIC-6 aluminum and 6061 aluminum. 

	MIC-6 Aluminum	6061 Aluminum
Production Method	continuous cast	flat-rolled or extruded
Form	plate, bar	plate, bar stock, rounds
Surface Finish	milled to 20 RMS or better	typically brushed to 60-90 RMS
Corrosion Resistance	average	excellent
Machinability	excellent	average
Weldability	limited	excellent
Best Uses or Applications	precision machining and instrumentation	structures and components where strength and corrosion resistance are required

Where To Purchase Mic-6 Aluminum and 6061 Aluminum 

Industrial Metal Service carries MIC-6 aluminum and 6061 aluminum sourced from Arconic and Kaiser, respectively. We also offer verified remnants of both of these alloys at a reduced price compared to new stock. Many machinists find that the remnant option is ideal for making prototypes or producing low-quantity production runs.