STAG Heavy Duty Aluminum Rear Sprocket - 52T PRO, Red for the Surron Light Bee

7075 aluminium inner with a hard wearing steel outer ring.

Stag Aluminium Sprockets are all made from 7075 -T6 Aluminium
We do not use 6061, even though it is cheaper and easier to machine due to its lower tensile strength and lower hardness.

Mechanical Properties
Both 6061 and 7075 are heat-treatable, so their mechanical properties cannot be compared accurately without assuming the same type of heat treatment. When looking at both alloys in the -T6 condition, several noticeable differences are observed. First off is that the tensile strength of 7075-T6 is nearly double that of 6061-T6. The shear strength of 7075-T6 is roughly 1.5 times that of 6061-T6. The former is substantially harder as well.

Applications
There is much application overlap between the 6061 and 7075 aluminum alloys. Both are used for bike parts, aerospace components, and building construction. They differ in these areas on how they are used though. For instance, in the aerospace industry, 7075 may be more likely to be used as a gear or rod, and 6061 may be more likely to be implemented in an area that requires more ductility. With bike parts, serious riders prefer the increased strength that comes with the 7075 aluminum alloy.