Strongest / Stiffest Metal tubing?

Tools, Techniques, and Reference Materials Tools
1

A very important part of my never-ending quest to construct a “practical” contra-prop gearbox depends heavily on the tubing I use to construct the prop shafts out of. Therefore, I need to know what type of SMALL diameter tubing is most resistant to bending. I started with brass tubing, but because my inner prop shaft was so small, it was basically brass wire. This bent very easliy, and led to the cancellation of that prototype. Today, in my infinite wisdom, I decided to try again, with larger diameter tubing (smart) made of aluminum (dumb). I found out rather quickly that this bends easier than the brass! [xx(] Back to the drawing board…

I’m tempted to try again with the thicker brass tubing, but before I go out and spend any more money, I just wonder if there is any material out there more resistant to bending than brass is. If anyone can offer any insight, it is greatly apprecaited.

When I say small diameter, I mean really, really small. I don’t have exact numbers right now, but it’s about a small a tube as you can get without filling the middle in and turning it into wire.

Thanks!

2

Steel would be your best bet. The question is where to get it. Talk to someone in the medical field. If you can get and exact size, I’ll see if my mom has any ideas. She builds hospital equipment.

3

Try Small Parts at smallparts.com

The Titanium tubing may be overkill http://www.smallparts.com/products/descriptions/tt.cfm

but the steel or stainless tubes may fit the bill

http://www.smallparts.com/products/descriptions/zrcm%20%26%20cmt.cfm

http://www.smallparts.com/products/descriptions/gptx-mgptx-gpsx.cfm

You can even get it in hypodermic sized diameters

http://www.smallparts.com/products/descriptions/htx.cfm

4

Small Parts has both stainless steel and titanium tubing. They also have other very small components. They are a pleasure to deal with, and delivery is generally fast.

5

Ed beat me by a minute. Is no speed to great for these terrible servants of Styrene?[(-D]

(With apologies to JRRT…)

6

That is totally awesome, guys. Thanks to you, I may actually get some progress done! WOO HOO!!

7

Steel is a good choice but there are lighter things out there. My recomendation is look up material property tables on the net and you will be able to find your answer. Titanium is also a good choice but can get expensive and I have heard it is hard to work.

Go to
http://www.matweb.com/index.asp?ckck=1

It is a free database with a lot of materials, you might find what you are looking for there.