Hey all, I'm a bit new to SolidWorks so sorry if this question seems a bit dumb or amateurish. Basically I have a hollow cylinder (with the correct dimensions I need), where the inner radius increases in diameter throughout (I added a draft). My goal is to cut this cylinder in half, and then have the 2 halves attach to eachother via a snap hook and groove.

My attempt:

Using split: When I tried to cut in the cylinder in half, I made a rectangle that completely intersected the cylinder on all sides on the front plane, and then I extruded it to a 1 mm thickness. Then I used the split feature, slected the prism and cut the 2 in half. To get rid of the prism I used an extrude cut of another prism of the same dimensions. What ended up happening is that I actually cut 1 mm off of the cylinder. Am I missing something obvious here? All I want to do is to cut this thing in half; the orginal outer diameter is 45 mm so the 2 halves should have 22.5 mm in outer radius.

Using the snap hook and groove: I had a lot of trouble with this one. I'm not even sure if its possible in this case, since Im trying to use it on a cylinder. My end goal is to cut this cylinder in half and then have them attach convieniently, so I'm trying snap hooks. What I tried to do is define a reference plane to position the snap hook correctly, and I think I might have gotten that, but then changing the dimensions so that it fits right has been a nightmare thus far. Since the diameter changes I know the 2 snaphooks (I planned on adding one towards the very top and one towards the very bottom) will be different, but my understanding is that if I can get this, then the grooves shouldn't be hard. Can anyone help with this?

I'll add the cylinder I'm talking about, but I can also add my attempts at the solving these issues if anyone wants to see those too. Any help would be hugely appreciated.