What is this in the hinge used for?

[whall3y]

The hinges on my doors include this which seems (at least to me) to serve little purpose - Thought it might allow hinge adjustment but can't see how it works. Not needed for any adjustment at present just asking for future reference.

 

[foxhole]

I think the square plate rotates with the aid of a screw driver in the slot after loosening centre screw, the raised dot marks position and can be moved to the 0,+1 or +2 positions.

 

[whall3y]

I think the square plate rotates with the aid of a screw driver in the slot after loosening centre screw, the raised dot marks position and can be moved to the 0,+1 or +2 positions.

Thanks, yes. But I'm not sure what effect it has on the door alignment by doing this? Especially as the screws above/below are fixed? Is it something used at installation time only?

 

[gonch69]

As above on the squares centres for adjusting toe but you also need a cranking bar to adjust hinges left an right youo see these hinges on cheap door setts used in new builds normally

 

[whall3y]

Thanks. Found a video for it: https://www.redrow.co.uk/tv/videos/howto/internal-door-adjustments