What kind of screw is it?

[Serfi]

These screws/rivets/nails? are on the grille in the basement that is inside the window. Question 1: What kind of screw is it, or is it a nail? Question 2: How do I remove it without damaging the window frame? They are really tight.

 

[Lärospånet]

Here you have a thread with the same question: https://www.byggahus.se/forum/threads/fa-loss-saekerhetsskruv.69050/

 

[RapidSledge]

http://www.sifvert-skruv.se/produkter/sakerhetsskruvar/

 

[RapidSledge]

Drill away the skull or make a groove in the head with the angle grinder or reciprocating saw.

 

[Isakare]

Drilling/sawing won't work as the screw is hardened, angle grinder works.
There are special bits for unscrewing them, I recently lent my bit to a member here on BH.

 

[RapidSledge]

Drilling/sawing is not possible since the screw is hardened, angle grinder works.
There are special bits for unscrewing them, I recently lent my bit to a member here on BH.

https://www.ahlsell.se/10/verktyg--...nga---sagblad/stick--och-tigersagblad/473112/

Drill, cobalt, carbide tip

Possibly cooling spray + hammer

 

[Isakare]

The shape of the skull makes it extremely difficult for a drill to grip.
I promise I've tried, before I bought the bit set.

 

[Isakare]

Sawing there without damaging anything else is tricky, especially if it's not something you do daily.

 

[A-Man_08]

Depending on the environment, welding on a nut might be an option?

 

[RapidSledge]

Sharp chisel and hammer to loosen it a bit, then something like a pipe wrench.

 

[richardtenggren]

I have used a dorn with good results.

 

[tergo]

read post 25 https://www.byggahus.se/forum/threads/fa-ut-saekerhetsskruv.330383/page-2

 

[A-Man_08]

Don't know how tightly threaded these are, but maybe it can be done with a welding pliers and twist it out?

 

[Robert-san01]

Make a groove with a Dremel and cutting disc. Then unscrew it with a regular flathead screwdriver.

 

[Isakare]