I am having some trouble fitting a Screfix "Universal Semi Flexible
Disc 115 mm on (Quote No: 18886)" on to a "115mm M14*2.0 Nylon Backing
Pad 22mm Hole" (Quote No: 12966); the locking nut doesn't reach the
thread when the disc is placed between it and the pad. Am i
assembling this right? I can see how a thinner aluminium oxide disc
could be pressed down so that it is sandwiched between the two but the
semi flexible disc is not giving much.