Fixing floating shelf to solid wall

[Apophany]

Hi,

I bought a shelf which I would like to fit to a solid wall in a Victorian property. The wall is the dividing wall between us and the neighbour, so I assume it's brick. From what I've read they tend to be about 225mm thick, so I should be safe to drill in to at least 100mm?

The shelf is floating, and I've attached a picture of it. From what I understand it needs to be fixed on to a screw, or something similar and then will slide on to it? The opening is just under 10mm, so any screw head would need to be less than that.

Can anyone recommend a fixing which would support the appropriate weight (we're thinking about 15kg-20kg) and would be small enough to fit in to the slot?

I bought these: https://timco.co.uk/50050HF-nylon-hammer-fixing-pz-zinc

But I need the screw to be fairly flush with the wall so the shelf doesnt protrude. I cant find any information about hammer fixings to see if its fine to screw it in past the thread so that only a small portion of the screw is actually protruding? Also it doesn't say how much weight it's expected to hold.

Thanks!

 

[Wayners]

100mm deep? 50- 60mm is enough imo. Need to hit brick not the mortar.
Pan head screw. Fisher red plugs. 6mm dewalt extreme drill bit and go on slow drill speed. Hammer off to start hole.

Really need pan head screws. That's how I'd do it

 

[foxhole]

You need screws in wall plugs , hammer fix have little pull out resistant and don’t offer fine tuning required to get a tight fit .