6061

[Jflyer]

On some other threads, there has been some discussions about where to find 6061 T6 for the cap strips and spacers.
For a different project, I just purchased from Fastenal, two 12 foot lengths of aluminum that is 1/4" thick by 3/4" width. It happens to be 6061. I asked the employee if he knew which hardness rating it was. T3,T4, or T6. He looked it up but did not have any reference to it in the catalog. All the other aluminum stock they sell, clearly stated 'T6' (round tubes, square tubes etc.). He is planning to contact the home office and see what he can find out.

However, printed on the material itself is . "6061 T6511" Does anyone know if that is T6 and if so, what is the 511 after it stand for? See photo.

If this material can be used for cap strips, each 1/4" X 3/4" X12' piece cost $21. No shipping charges if your picking up at the local Fastenal store
They have a variety of sizes and thicknesses.

[Isaac]

Interesting question. The best I can tell, the T6511 designation just means that the material has had some additional steps performed on it during the manufacturing process.

McMaster Carr website has this information on aluminum alloys and temper designations.

T6 Solution heat treated and artificially aged
511 Stress relieved by stretching with minor straightening

So material with a temper of T6511 has been solution heat treated, artificially aged, and stress relieved by stretching with permissible minor straightening.

Here is some additional info found on the internet:

To get to the -T6 temper, the 6061 is heated to about 990F, then quenched in water, then aged at about 350F for around 8 hours. That changes the typical yield strength from 8 ksi to about 40ksi.

The quenching in water puts residual stresses in the aluminum, since there is a surface-to-center cooling gradient. The -T651 designation means the mil took the extrusion and gave it a 1% to 3% stretching or permanent set to get rid of some of those residual stresses. Now it can be machined at it shouldn't distort.

The final digit in the -T6511 designation means that the mill straightened the extruded bars, like in a press to get them to meet the straightness tolerances.

The link below is to a .pdf Alcoa Aluminum document that indicates that T6 and T6511 have the same material strengths and characteristics/

http://www2.galcit.caltech.edu/~tongc/html/data/elastic/Extruded_Alloy_6061.pdf

[mswain]

I found this just googling the number you posted. Seems like it refers to stretched 6061-T6.

http://www.aluminumgrips.com/pages/w...1-aluminum.php

Also, 6061 is a common alloy used in Marine fabrication....so you're local marine fabricator can probably get it easily. I would have got my 6061 locally but the Bearhawk 4 place required 14' length for the rear spars....Wicks was the only place I found that had it over 12'.

[Jflyer]

Impressive Info... Thank you.
Obviously I came to the right place with my question.