Here can purchase of screw back  13mm. Chicago screw studs 

in 3 colors: Nickel ; Antique Brass and Black Nickel

they are made from solid brass

Оne set includes  one Chicago screw and one screw .

for dimentions,please see the second picture.

The capacity of the binding screw is the distance in between the two heads when closed.

Threaded post lets you open and reattach pieces when needed.

Note: to choose a quantity  and color use a drop down menu above