7005 aluminium alloy

7005 is an aluminium wrought alloy^[1] used in bicycle frames. Due to its relative ease of welding, it does not require expensive heat treating. It is, however, harder to form, making manufacture more challenging.^[2] It has an Ultimate Tensile Strength of 350 MPa, a Fatigue Strength of 150 MPa and a density of 2.78 g/cm³.^[3] It does not need to be precipitation hardened, but can be cooled in air.^[4]

Bicycle frame made out of aluminium alloy

Specific forms of AL 7005 include

1. 7005-O
2. 7005-T5
3. 7005-T53
4. 7005-T6^[5]

Chemical composition

The alloy composition of 7005 is:^[6]

7005 Aluminum alloy

No	Element	Percentage
1	Aluminium	91.0% - 94.7%
2	Chromium	0.06% - 0.20%
3	Copper	<=0.10 %
4	Iron	<=0.40 %
5	Magnesium	1.0% - 1.80%
6	Manganese	0.20% - 0.70%
7	Silicon	<=0.35%
8	Titanium	0.010% - 0.060%
9	Zinc	4.0% - 5.0%
10	Zirconium	0.080% - 0.20%
11	Other, total	<= 0.15%

Properties

No	Property	Value
1	Density	2.78 g/cm3
2	Elastic modulus[1]	70-80 GPa
3	Poisson Ratio[1]	0.33
4	Thermal conductivity[1]	166 W/mK
5	Ultimate Tensile Strength[1]	350 MPa
6	Fatigue Strength[1]	150 MPa

Further reading

• Aluminum 7005-T6 Properties
• Aluminum 7005-O Properties
• Aluminum 7005-T53 Properties