Rear tie down loop bolt

Installed the RagoFab bed stiffeners and the torx bolt fits but it’s not using the washers and lock washer. Toyota is no help on a different bolt that is 1/2” longer. Home Depot bolt sizer calls it 7/16”-20 threads per inch. The replacement bolts I bought are too small diameter.
I guess I can spend $12 on Amazon for two grade eight 1/2”-20 bolts cuz why not?
Anyone know for sure what to use for the loop tie down bolt? Thanks.

 

Pretty sure all the stock fasteners are metric... no?

 

Im just regurgitating what the bolt sizer told me it was (wasnt!).

 

I have Rago stiffeners has no issues installing them with what I received and leftovers from the bed. Did you snap a bolt? The instructions tell you to pry off that washer and reuse bolt which is what I did and mine all fit fine.

 

I reused them both but without the lock washer I’m worried it will loosen. A longer hex head would solve that.

 

2-3 drops of blue locktite on the threads will eliminate your worries.