Question for everybody on aluminium material replacement.

My plan for CH640 Fuselage required "L" longeron made from 6061-T6, 0.093 thickhness (3/4" x 3/4"), but my local provided is back order on this material.

He propose me 1 x 1 x .125 thickh, but in 6063-T3 alu. Could I replace it by this one ? or other any other material like 2024-T4 could be use (in same or other thickness).

What are my alternatives ?

Christian Tremblay

CH640 scratch build from plan

Views: 253

Reply to This

Replies to This Discussion

this site might give you the info you are looking for. 


"The bearing yield strength is a measure of how a material will respond in joining arrangements; think when two metal plates are joined by a screw drilled through both plates. The bearing yield strength is the maximum amount of stress that will not cause this hole-joint to fail (stretch/crack) when the plates are pulled/pushed, and is a useful measure in applications such as in scaffolding where this arrangement is common. Again, 6061 is more often chosen for these applications as it has a much higher bearing strength over 6063 aluminum (386 MPa vs. 276 MPa)."

Tks Russell for referenced articles.

I will kept them in my reference builder documentation. Now I can choose alu alternative for replacement of extrusion if needed.


I don't know where Zenith buys is 0.093 3/4" equal L.  But it's not very common.

6061-T6 0.125 3/4" equal L is much easier to find.  The standard length for both of these extrusions is 25 feet.

tks Timothy for information.

I will try find it in this lenght, economy of longeron splice with 8 bolts installation for 4 joints.


do not use 6063 as it is an arcitectural grade and not suitable (it can be identified by a sharp inside corner where as the structural grades will have a radius on the inside corner). The .093 shown in the plans is propreitary to Zenith  at least here in the US. The common substitute is 3/4 x 3/4 .125 thick 6061-T6 and is commonly available. in the US it is less than $20 a length 

Tks Dan for Information.


Not doubting you, but it appears(IME) that the L that zenith uses has a sharp inside corner. The 601HD that I dismantled had a sharp inside corner. The plans(601HD and 650B) also show a longeron with a sharp corner. Not sure if this changed on the newer models, I have not ordered those parts for my 650B.


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Homecoming Tshirt:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Lavion Aero

K&S Aviation Services

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2023   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service