Spark plug container

I needed a container to take a fresh spark plug with me on off road tours with my dirt bike. There are several of these containers on thingiverse but these are too bulky for me, the spark plug was not clamped on the least fragile part and/or they had other aspects that I didnt like.... so I designed my own one.

The container fits one NGK BR7ES spark plug. I guess it also fits other brands but I am not sure that the shape is identical.

The upper half has ribs that makes it easy to hold for (un)screw.
As I foresee that the thread sticks if you try to open it on the track I added plenty of interfaces to open the container with wrenches. The bottom half has a hexagonal that fits the spark plug wrench. The ribs on the upper half fit in the spark plug wrench. There is also a 10mm hexagon on the upper half so plenty of possibilities to open the container whatever.

The halves are connected by M24x1 thread. After printing screw and unscrew the halves several time to get rid of small imperfections in the thread and to make it run smooth. With the axial grooves in the thread deformations due to layer shift should be minimal and run in should be much less needed. If you still do not get smooth running thread buy a cheap thread cutter like this one https://nl.aliexpress.com/item/1005005976000250.html?spm=a2g0o.order_list.order_list_main.56.6b4179d2TdqTbW&gatewayAdapt=glo2nld

In the container the spark plug is clamped between the upper and lower half on the hexagonal. All other parts of the spark plug do not touch the container. There is a picture of an open proto version of the container showing that attached to the thing.
On used spark plugs the sealing rivet at the end of the thread has a slightly bigger diameter due to being squeezed. I increased the hole to accommodate for used spark plugs.

You can add an O-ring to seal the halves. I bough these ones https://nl.aliexpress.com/item/4000126451077.html?spm=a2g0o.order_list.order_list_main.31.6b4179d2TdqTbW&gatewayAdapt=glo2nld