Hi Guys,

Thanks for the replies ! Since my post I finally figured out that they're 5 mm as you guys said. I wasn't too keen on the very fine thread and the difficulty in finding metric nylon bolts so I knocked the T-nut out and replaced all the hardware with 1/4-20. I also added a 1/4" ply plate in the fuselage to better hold the bolt in place when the wing is not on.