The filter thread size for the Raspberry Pi 6mm CS mount lens is 27mm.
Raspberry Pi 6mm lens with step-up-ring
The filter thread size for the Raspberry Pi 16mm C mount lens is 37mm.
Raspberry Pi 16mm lens with step-up-ring
You can use these lenses as macro lens by to reverse mounting them on the Raspberry Pi HQ camera. That works surprisingly good. See my earlier posts.
In short: you need a reverse macro ring adapter and some step up rings. I use a Pentax K-mount adapter and ring, because I have some classic Pentax glass, that can be also used with the Raspberry Pi HQ camera.