Excerpts from wikipedia:
6000 SERIES
The mechanical properties of 6061 depend greatly on the
temper, or heat treatment, of the material.
[1] Young's Modulus is 10x10^6 psi (69 GPa) irrespective of temper.
[2]
[edit] 6061-O
Annealed 6061 (6061-O temper) has maximum
tensile strength no more than 18,000 psi (125
MPa), and maximum
yield strength no more than 8,000 psi (55 MPa). The material has elongation (stretch before ultimate failure) of 25-30 %.
[edit] 6061-T4
T4
temper 6061 has an
ultimate tensile strength of at least 30,000 psi (207 MPa) and yield strength of at least 16,000 psi (110 MPa). It has elongation of 16%.
[edit] 6061-T6
T6 temper 6061 has an ultimate tensile strength of at least 42,000 psi (300 MPa) and yield strength of at least 35,000 psi (241 MPa). More typical values are 45,000 psi (310 MPa) and 40,000 psi (275 MPa), respectively.
[3] In thicknesses of 0.250 inch (6.35 mm) or less, it has elongation of 8% or more; in thicker sections, it has elongation of 10%. T651 temper has similar mechanical properties. The famous
Pioneer plaque was made of this particular alloy. The typical value for thermal conductivity for 6061-T6 at 80°C is around 152 W/m K. A material data sheet
[4] defines the
fatigue limit under cyclic load as 14,000 psi (100 MPa).
7000 SERIES
The mechanical properties of 7075 depend greatly on the temper of the material.
[2]
[edit] 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%.
[edit] 7075-T6
7075 tech sheet T6 temper 7075 has an ultimate tensile strength of 74 - 78,000 psi (510 - 538 MPa) and yield strength of at least 63 - 69,000 psi (434-476 MPa). It has failure elongation of 5-8%.
[edit] 7075-T651
T651 temper 7075 has an
ultimate tensile strength of at least 67 - 78,000 psi (462 - 538 MPa) and yield strength of 54 - 67,000 psi (372-462 MPa). It has failure elongation of 3-9%.
The 51 suffix has no bearing on the heat treatment but denotes that the material is stress relieved by controlled stretching.
According to this untempered 7075 is almost as strong as the best 6061.....Unless I'm missing something here which anyone can feel free to point out because I am definatly not an expert I'm just assuming whoever did the wikipedia write ups is
