for the geeks:

6061-O: has ultimate tensile strength no more than 18,000 psi (125 MPa), and maximum yield strength no more than 8,000 psi (55 MPa)

6061-T4: has an ultimate tensile strength of at least 30,000 psi (207 MPa) and yield strength of at least 16,000 psi (110 MPa)

6061-T6: has an ultimate tensile strength of at least 42,000 psi (290 MPa) and yield strength of at least 35,000 psi (241 MPa)

7075-O: has maximum tensile strength no more than 40,000 psi (276 MPa), and maximum yield strength no more than 21,000 psi (145 MPa)

7075-T6: 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)

7075-T651: 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). The 51 suffix has no bearing on the mechanical properties but denotes that the material is stress relieved by control stretching.

6061 isn't good enough. try 7075.

referees if necessary, but not necesarily refereeing