Polo Science: Lesson 1 - Aluminium 7075

7075 is an aluminium alloy, with zinc as the primary alloying element. It is strong, with good fatigue strength and average machinability, but has less resistance to corrosion than many other alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable.

7075 aluminum alloy's composition includes 5.1-6.1% zinc, 2.1-2.9% magnesium, 1.2-2.0% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals. It is commonly produced in several heat temper grades, 7075-O, 7075-T6, 7075-T651.

The mechanical properties of 7075 depend greatly on the temper of the material.

7075-O

Un-heat-treated 7075 (7075-O temper) has maximum tensile strength no more than 40,000 psi (276 MPa), and maximum yield strength no more than 21,000 psi (145 MPa). The material has elongation (stretch before ultimate failure) of 9-10%.

7075-T6

T6 temper 7075 has an ultimate tensile strength of 74,000 - 78,000 psi (510 - 538 MPa) and yield strength of at least 63,000 - 69,000 psi (434-476 MPa). It has elongation of 5-8%.

7075-T651

T651 temper 7075 has an ultimate tensile strength of at least 67,000 - 78,000 psi (462 - 538 MPa) and yield strength of 54,000 - 67,000 psi (372-462 MPa). It has elongation of 3-9%.

The 51 suffix has no bearing on the mechanical properties but denotes that the material is stress relieved by control stretching.

Now go and get some 7075 poles!

If you're gonna play you gotta know.