Looking for long narrow screw with small head

[dadid]

For fastening the connection ring to my air supply diffusers, I need a very slim screw.
I just can't find such a thing.
The screw would need to be about 70mm with a diameter of about 3mm.
Mounting screws are not suitable, as the holes are not very easy to drill up. They are so close to the edge.

25 Splinter panel
20 Plaster
23 Air gap
13 Gypsum
Ring of galvanized metal with holes about 3.5mm

Tips and ideas are eagerly awaited!

 

[fgo]

Glue around the edge. Could it work?
Or make new holes between the old ones

 

[basseman]

Search for list or sockelskruv

 

[dadid]

Search for list or sockelskruv

Good suggestion!
Unfortunately, there doesn't seem to be any listskruv longer than 57 mm unless they are "double-threaded," meaning that a thread under the head holds the list rather than the head, which is made very small.

Have you come across anything that contradicts this observation?

 

[dadid]

Glue around the edge. Could it work?
Or make new holes between the old ones

Edge gluing is the last resort. The floor above presses a little on the flexible pipes, so the risk is relatively large that the gluing won't be as good as I would wish.

 

[Jan271]

Can you access the back?
3 mm threaded rod, dome nut on the visible side.
Would that work?

 

[dadid]

Can you access the backside?
3 mm threaded rod, dome nut on the visible side.
Would that work?

Wish it were possible, but the lid is on (includes parquet and waterborne floor heating :-/

 

[InsidersUnited]

Deck screw with extra wooden patch in the attic)

 

[egge80]

I don't know what you're really trying to achieve, is it to make the nozzle fit tightly against the ceiling or just as a pure attachment to your flexible hoses? If it's just about the nozzle attaching to the flexible hose, you take a regular sheet metal screw (about 12 mm) and screw from the inside into the metal reinforcement of the flexible hose... yes that's how I usually do it anyway.

 

[mexitegel]

If it concerns the attachment of the flange to the ceiling gypsum, saw out a piece of plywood (about 7 mm), split it in half, and place it in the hole before you put back the flange and screw it in place.

 

[dadid]

I don't really know what you're trying to achieve, is it to get the flange to seal tightly against the ceiling or just as a pure attachment to your flexible ducts? If it's just to connect the flange with the flexible duct, you take a regular sheet metal screw (about 12 mm) and screw from the inside right into the flexible duct's metal reinforcement... that's how I usually do it anyway

Well, the flange is attached a bit too securely to the flex damper. That's part of the problem. I'm afraid I'll damage the damper if I remove the flange to access the air gap. A long narrow screw would be so simple

 

[KnockOnWood]

Take a screw of sufficient length, maybe 5 mm dia. And washers in the appropriate size for the screw.
And place the screw outside the edge of the stosen, so the washers hold the stosen.
The valve cover that should go there has a large enough diameter to hide the screw, right?

 

[dadid]

7.5 mm margin. A tough task.

 

[Fulkemisten]

Contact Sifvert-skruv. They know everything about fastening. If they do not have the screw in question in stock, they can probably find it. According to their own information, they can sometimes manufacture screws as well. www.sifvert-skruv.se

 

[Peter2400]

A bit long maybe, but it might not matter, you should be able to fit 3.5 mm, right?
https://www.hornbach.se/shop/Regelskruv-FXTB-3-5x100-mm-FZB-10-styck/8498107/artikel-detaljer.html