Clips for undermount sink

[Abyone]

Had to re silicone around my under mounted stainless kitchen sink set in a granite style worktop.

I lowered the sink and when I did some of the clips fell out.
I couldn't get the clips to stay in place after that they kept falling out.

There is a small groove with a hole in the centre when the bolt part of the clip goes up into the worktop but I can't figure out what keeps it in place.

Should I get new clips and if so what type
See photos of current setup.

 

[blup]

IIRC I used a small trolley jack and a block of wood to hold tne basin in place while the sealant set, then fitted tne clips in place afterwards. I also used some undermount sink brackets from ebay as I didn't trust tne sealant and clips, probably unnecessary in hindsight but gave peace of mind as it was first time fitting

 

[Madrab]

The threaded rod need to be tightened up into the expansion nut to spread the end out. Basically they are Rawlbolts without the head on the threaded rod

 

[Abyone]

The threaded rod need to be tightened up into the expansion nut to spread the end out. Basically they are Rawlbolts without the head on the threaded rod

When I tighten it up the bracket clip just rotates around, the expansion nut doesn't bite.
So would I better swapping the threaded rod with a bolt or one with a head so I can tighten up enough to spread the expansion nut ? Otherwise I can't seem to tighten it.

Edit: have been googling and I came across drop in anchors - is that what this is ? If so do I need a setting tool to expand it before I insert the threaded rod?

 

[jj4091]

and https://www.google.com/search?q=und...kgcCMTagB_tTsgcCMTS4B7sH&sclient=gws-wiz-serp Perhaps a suitable alternative.

 

[Madrab]

I think it's basically worn out, so it won't grip any more. Not really drop in anchors as such, they are dropped into a hole in concrete and then use the spreader bar to hammer them tight, not what would happen on a worktop I wouldn't think. You may need to get the standard clips, cut a few new slots and use them. They are certainly the better type.

The glue type I have found, all seem to eventually fail IME.

 

[Abyone]

I think it's basically worn out, so it won't grip any more. Not really drop in anchors as such, they are dropped into a hole in concrete and then use the spreader bar to hammer them tight, not what would happen on a worktop I wouldn't think. You may need to get the standard clips, cut a few new slots and use them. They are certainly the better type.

Thanks - what do mean by the standard type.
A lot of what I have seen rely on epoxy which I would like to avoid if I can.

Also, how easy is it to cut slots or holes into a stone worktop ? ( It's one of those reconstituted stone types I think, not natural stone, but for all intents and purposes it's comprised of stone)