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6061, 5052 or 3003 for custom parts ?

H

humptybump

Well Known Member
When people are bending up small brackets, mounts, and the like, which type of aluminum sheet material and thickness do you use?

Examples of things I need to create are a GPS antennas mount for under the cowl, a small bracket for the remote compass sensor, a bracket for the AHRS, etc.

These brackets will most likely be formed using a box brake.
 
2024T3 .025, same as the majority of rest of the bent parts in your airplane (ribs, bulkheads, etc.)
 
2024

+1 on the 2024, but you might have to make some modified tooling for your brake to bend the material at a relatively large radius. Sharp-nosed tooling will crack or weaken the material every time.

On my brake, I formed some thin steel sheet to fit over the nose of my sharp dies, and taped it in place. This creates a larger nose radius and solves the cracking problem.

M
 
Glen,
Items made from sheet aluminum should be 2024-T3. Pieces made of angle can be made from 6061-T6, as that is what Vans uses.
Charlie
 
Down at thicknesses like 0.025, bending 2024 is feasible. I'll do a test for one bracket. For thicker material, 2024 will crack.
 
Read Chapter 4 of AC 43.13-1B

humptybump said:
Down at thicknesses like 0.025, bending 2024 is feasible. I'll do a test for one bracket. For thicker material, 2024 will crack.
Click to expand...

Actually, it quite easy to bend even .050" 2024-T3 if you use the instructions outlined by Matthew above. Vans makes several spars out of .050" sheet in your kit. [aileron spars for one]. Instructions can be found in publications like SHEET METAL 101 or the FAA's AC 43.13-1B [Chapter 4] You can download AC43.13-1B for free from the link below. This document should be considered a "must have" for every RV builder.

http://www.faa.gov/regulations_poli....cfm/go/document.information/documentID/99861

Other useful, free info available from the FAA are items 4-8 from the link below. They are study manuals for A&P candidates.

http://www.faa.gov/library/manuals/aircraft/


Charlie
 
Last edited:
Thanks for the reference material.

chaskuss said:
it quite easy to bend even .050" 2024-T3 if you use the instructions outlined by Mathew above.
Click to expand...

The challenge with 2024 is the bend radius. With 0.050, the minimum inside radius is 1/4" - which may not always be viable.

I'll work with 2024 where I can and a softer alloy where I must.
 
Bend across the grain!

Remember when bending sheet aluminum, regardless of the alloy, always bend across the grain whenever possible.
Bending with the grain invites cracks.
 
Mel said:
Remember when bending sheet aluminum, always bend across the grain
Click to expand...

Thanks Mel. I just "googled" the subject of aluminum grain. I found a number of comments that repeat what you just said. However, I could not find any place that tells me how to identify the direction of grain in the aluminum.

Is it obvious ?
 
6061 tends to be more brittle than 2024 but you can still bend rather thick sheets of 6061. The temper "T" number is more critical with 6061. You can buy 6061 T0 or you can anneal it with an oxy/ace torch. Light the torch with just the acetylene going and blacken the material where the bend is going to be and then turn on the oxy (with acetylene) to make a normal flame, now burn off the black, being careful not to overheat a single point and melt a spot in your sheet.
 
humptybump said:
Thanks Mel. I just "googled" the subject of aluminum grain. I found a number of comments that repeat what you just said. However, I could not find any place that tells me how to identify the direction of grain in the aluminum.
Is it obvious ?
Click to expand...

If it has the mil marks, they normally run with the grain.
If you look at the aluminum you can see the grain. It's not real obvious, but it's there.
 
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