metric screws and a/nuts ? 1

[rb1957]

Hi, we're designing in NA (the last hold out for the Imperial system) but are mounting a European antenna (for a plane to be operated in Europe) with metric holes (M5.5). I'm being told that there are very limited options for metric a/nuts (only clikbond). I want to call BS on this. Unless it is common practice in Europe to use imperial a/nuts with metric screws (which I find hard to believe).

Can someone comment please ?

Yes, helicoils are an option ... so we could make our own "a/nuts" ... a strip of Al with helicoils and interpitched rivets attaching strip to skin ... UGLY !

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[rb1957]

not on this side of the pond !

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[WKTaylor]

The ONLY US fasteners I'm aware of, with countersinks close to 90-deg, are reverse driven protruding head rivets into 89-Deg NACA countersinks in thick structure.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[rb1957]

Yes, typically imperial screws have 100 deg CSK, and typically metric screws have 90 degrees ... viva la difference !

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[berkshire]

RB,
You have probably looked here, but if you have not, this may be a good place to look:

https://www.clarendonsf.com/products/bolts-screws/aerospace

,
Having worked for about 40 years on both German Sailplanes and motor gliders. The Europeans tend to use two standards, the LN (Luffshart national) or on more lightly loaded parts the DIN standard mostly grade 8.8.
Now I may be telling you something you already know. If not, this may be useful, If you already know it, then I stand corrected.
B.E.

You are judged not by what you know, but by what you can do.

 

[WKTaylor]

Berkshire 23 Apr 23 21:17... very useful website... Thanks!!

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov