What’s the difference between 7075 T6 and T73? Now that we are stocking 7075 T73 sheet, we’re here to answer this commonly asked question!

Differences between T6 and T73?

While T6 is the stronger, more rigid of the two, it tends to more vulnerable to stress cracking. It is heat treated and aged to the maximum strength possible for the 7075 alloy.

By comparison, T73 has lower strength, more flexibility, and provides a better product in extended high stress environments. To reach this state, the material is heat treated and aged to T6, but then they continue aging it. By overaging the material into the T73, it loses some strength but increases in durability. It is also more corrosion resistant.

Toughness decreases along with temperature for aluminum 7075. And for this reason, T73 is better suited for extremely low temperature applications such as cryogenics.

If you are looking for specific numbers and hard data, check out our Product Guide for 7075 aluminum.

Uses for each temper

7075 is the strongest of the aerospace grade aluminum alloys. The first airplane that used mass amounts of 7075 aluminum was the Mitsubishi A6M Zero. The fighter’s legendary maneuverability was largely due to the superior strength to weight ratio of 7075.

Both tempers are still used in airplanes, spacecraft, and other high strength applications. In these situations, T6 makes up the bulk of the parts. T73 is used for components that need to be more flexible or routinely undergo high and continual stress. The bases of aircraft wings are a prime example. Gears, valve parts, shafts, and landing gear are more commonly made from T73.

Here is a list of some other common uses:

  • Marine parts,
  • Automotive parts,
  • Rock climbing equipment,
  • Bicycle components,
  • Hang glider frames,
  • High end gears, shafts, & valve parts,
  • High end RC models,
  • Lacrosse sticks, and
  • High end firearm receivers

If the part needs to undergo continuous high stress, T73 is preferred over T6. If the part endures extreme stress for shorter durations, choose T6.

Would you like to know more?

What’s the big difference between 7075 aluminum and 6061? We have a post about that too.