wires
there seems to be a few conflicting data sheets on 12x3 trapezioid screw mine came from marchant dice and with just the thread ground off a 8mm skate bearing will not go on ... needs a tad more taken of with a file to get a snug fit , so i think with just the thread off 8.5-9mm


http://www.roymech.co.uk/Useful_Tabl...apezoidal.html