Bolts

Whoa. Time flies. Not our Aero, though.
Let me just say that in the first 50 days of the year, we reached our yearly plan for composite production. Enough said.
Somethings were still done on the Aero. This time I'd like to present the research work done on bolts. There were several bolts that were either damaged or corroded to such extent that they need to be replaced.
One thing that we constantly keep in mind regarding this aircraft is that it is heavy. H E A V Y.
Therefore all the primary structure must really be top notch and we have to be confident in it.
So we ran a tensile test on some samples of metal.

The image above shows three samples. One is a sample turned from an original bolt, the other is a material that I thought was suitable for new bolts, and the other is simply a 8.8 normal hardware bolt.
The result of the test was not so hot.

As you can see the normal hardware bolt peaked at 640 N/sq.mm as it should. The strongest bolt was the original one at 1000 N/sq.mm and the CrMo that was my best bet before the test reached a little over 800 N/sq.mm. Back to the drawing board, but this time it is much easier, since we know what we have to replace.
Another two samples are prepared. One again from the original bolt and another from the a different CrMo steel. So it is time for another test.

This kind of work is exacting and it does eat away at the time, but it has to be done. Imagine putting a normal hardware bolt replacing the high tensile old one and crossing your finger...
I won't promise to keep the blog more up to date, but I will certainly try to.
Have fun, enjoy the spring!