Help in identifying elements used on LEGO Batman movie's Daleks
It looks like Minifig, Utensil Tool Box Wrench - 3-Rib Handle
Item No: 11402i (although it looks like the ribbing may have been omitted in the CGI model):



The socket end can clutch a stud, so it can be attached there.

This newer variant of this piece has come in flat silver, which is probably the closest color so far if not the color, in 5 different sets so far.