What is a good way to put on the 1/2" to 3/4" adapter shims ? I bought about 40 of these things at $0.10 a piece and am having trouble putting them on. I've seen the video on the product page and it looks pretty easy, but it is not working for me. The shims in the video are Sharkbite brand, all white. The ones I got were BOW brand, and mostly black with a white outer layer.

Just googling dimensions from the internet, the inner diameter of 3/4" EMT is 0.824", and the outer diameter of 1/2" EMT is 0.706. The difference is 0.118", and divided by 2, that should be the thickness of the shim, 0.059". But when I measure the thickness of my shims, it is 0.1095". The PEX material is not compressible.

I also measured my conduit with calipers. The inner diameter of my 3/4" EMT is 0.79", and the outer diameter of my 1/2" EMT is 0.71". The outer and inner diameter of my (relaxed, not attached to anything) shim is 0.82" and 0.61", respectively. So to fit the shim inside the 3/4" pipe, where the o.d. of the shim is 0.82" and the i.d. of the 3/4" EMT is 0.79", that means that I have to squeeze the shim to a smaller diameter. However, to fit the shim on the outside of the 1/2" pipe, where the i.d. of the free shim is 0.61" and the o.d. of the 1/2" EMT is 0.71, that means I have to expand the shim to a larger diameter. These two requirements are in opposite directions, meaning I have to compress the material, but the material is incompressible. I can get it to fit inside a 3/4" EMT, and I can get it to fit over a 1/2" EMT, but not both at the same time. The white outer layer on the shim does not come off; I reckon it's not supposed to. When the shim is over the 1/2" EMT, the outer diameter of that ensemble is about the same diameter as the outer diameter of 3/4" EMT.