Jax Z1 thread size?

I have a Jax Z1 flashlight. I want to replace the stock aspheric lens that measures approximately 42mm in diameter with one that measures 50mm in diameter. I would need to machine a new case for it and I would like to ask if anyone knows what is the thread size that threads onto the body of the flashlight?

It’s not a standard size, it’s whatever the designer felt would be easiest for the machines.

The real question is why, that 42mm perfectly AR coated lens is the number one selling point of the Z1, any performance gains from a slight diameter increase going to a 50mm lens will be negated by the lower quality of the lens. Unless you’re gonna be using a $80+ lens from Edmunds optics its really not worth it and at that point you may as well start with a totally custom designed host (or atlease something not as nice as a Z1).

Just my opinion. The Z1 is an incredible light on its own. The amount of work your looking at you’d be better off with a total custom (probably wouldn’t be much, if any more money either, since the machinist would have free rain to make all the threads whatever he wanted instead of trying to match some unknown Chineese threads).

Not to mention a different lens will have a different BFL (back focal length, distance from the back of the lens to the die) so it’ll need to have the heigth of the pull adjusted as well.

I tried using a 50mm lens for a quick testing and I get about 40% more lux reading at 1m, so the effects are not negated. I got this 50mm lens from DX for less than $4. I will also consider machining the flashlight from scratch though. The other alternative would be to find a body from a different zoomy flashlight that would work with a 50mm lens and a 50mm BFL but so far I haven’t found any.