"bob" wrote in message
...
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.

My grinder uses a different fitting for the backing pad than for a grinding
disk

If you are using the nut as your post suggests this is wrong for sanding
disks

You need to use the flat threaded fitting with the 2 holes in for the
sanding disk & backing pad

You may need to push it in a bit to get it started

Tony