Light Aircraft Association

I am ready to order 4130 sheet for my Pietenpol fittings and would like a confirmation that Normalised is the spec to go for rather than Annealed.
Normalised is harder and would seem to be the grade to go for out of choice.

Also it seems laser profiling is not recommended due to edge hardening, is that fact?

Many thanks
Trevor

I've just had some pieces waterjet cut from 4130N (normalised) for my Menestrel which worked well. The stuff is quite hard to bend in that state, 2mm thick material needed none too gentle persuasion with a lump hammer (and wooden block of course). I built a small press brake to bend up hinge halves from 1.5mm.
Tony R

Thank you for your reply Tony.
This information was not forthcoming doing a search and is not identified on the plans.
LAS will seemingly supply annealed sheet if normalised is not in stock which indicates either will do.
That might not be the case for engine mount fittings for example.
I am concerned with one fitting that does need a considerable bend and hope it does not crack using the harder less ductile material

The laser or water jetting question does not appear to be documented either which was partly why I originally posted.

Trevor

Metal fittings :-
To confirm Water Jetting works very well indeed as long as the material is rubbed down before and after with an oil based cloth. A real concern was the sheet being left damp and as such rusting easily.
Very pleased with the end result and the fettling time saved.

Just a word of caution: be careful about the actual state of the raw material. At work (aircraft maintenance) we received some metal sheets we intended to use for some repairs which the data and conformity sheets indicated was supplied in the annealed condition. Subsequent closer investigation revealed that although the headline on the data sheet identified the material as annealed it was actually normalised and required subsequent treatment to achieve the annealed state - the devil was in the detail some way through the sheets.

Hayden.

Trevor

This should be answered by your inspector. If it is not specified on the drawing then the supporting Design Authority needs to give you the answer. In this case it is the LAA. The wrong state in the wrong place would be a disaster.

Roger