Allgrip Thunderbolts M8 x 75mm, supplied in a box of 100.
Concrete screw bolts cut their own thread directly into a pre-drilled hole in concrete, brick or stone, giving a strong mechanical fix with no plug or expansion sleeve. Drill to the correct diameter and depth, clear the dust and drive the bolt with a socket or impact driver.
Removable and reusable, and suitable close to edges where an expansion anchor would split the substrate.