Insulation washer/hanger

I'm converting my garage into a maker space and decided to use rolls of rock-wool insulation instead of kingspan.

I already floored its loft space for storage so had to get a little creative on installing insulation upside down in the joist space before i could put up plaster board and came up with this.  I suppose you could use them in any orientation or as a big cheap washer.

It's 50mm in diameter about 6.5mm at its peak and 2-2.5mm thick away from the screw hole. 

The hole is 11mm at the base tapering down to 5mm at the top to suit a wide varieties of hardware.  

It's pretty much a cheap wide plastic washer but I couldn't find anything in B&Q even remotely close so designed it in Tinkercad.

You can easily fit 16 to a bed at around 71grams of material total.

Its not going to be the most popular of models but i suppose even the obscure ones serve a purpose.