eerrrrr

been looking at how to determine which rivnut/nutsert size i need to fit the bolt below. im pretty confused from what google search comes up with. couple articles/threads say i need M14 because thats the size of the bolt head, but that doesn't make sense because the thread pitch is M10x1.25.

Need this bolt:
https://drive.google.com/file/d/1vS2...ew?usp=sharing

in here:
https://www.instagram.com/p/CDuBBvmHN6T/

per fsm, this is the bolt im referring too:
https://drive.google.com/file/d/1FZf...ew?usp=sharing