Bralo countersunk aluminium multigrip rivets bralo 1090004812 these countersunk multigrip blind rivets from bralo have an aluminium body and a zinc plated steel mandrel multigrip rivets offer a wider gripping range than standard rivets these pop rivets have a thread diameter of 48mm and are 12mm long bralo 1090004812 countersunk aluminium multigrip rivet 48mm x 120mm pk 250