C-4 rear hub/bearing torx bolts

[boomdriver]

Does anyone know what the grade is for these 55mm torx bolts? I would think that its grade 8.8 min but not sure. Is that an SAE grade or metric?

I'm looking at possible replacements.

 

[surfer93]

It is metric and I believe it is 53mm, do a search on hubs. I saw hub bolts for sale and you should be able to identify the type.