You can take a look at the photo below what i've done to fit the bolt:![](http://www.geocities.com/super_bq/HiFi/4Pi/4Pi_CD_Screw.JPG)
The local fastener shop had a hard time identifying the alen key bolt to fit in. On the invoice the description of the bolt is "Socket Cap Screw - 6 x 16". So i assume 6mm head x 16mm long for the inside 3 bolts. $1.35NZ each so (60 cents US each).