Nut: M5
Bolts:
M5x12
M5x16
M5x20
M5x25
Link to other Sizes:
M4: https://makerworld.com/en/models/243605#profileId-259987
M6: https://makerworld.com/en/models/243624#profileId-260008
M8: https://makerworld.com/en/models/243632#profileId-260016