JIS (Japanese Industry Standard) bolt pitch for undertray

[Aeroelastic]

Hi got a plastic tray for the centre diff area as mine was missing. When I tried to insert my own standard bolt (M8 with 13mm hex head) to the existing tap hole, it is almost different thread or difficult to screw the bolt in. Big force is required so I stopped in order not to damage the existing tap hole.

my question is do I need to get special JIS bolt with fine thread? I checked online and it said M8 pitch thread is 1.25 for JIS, same as standard M8 bolt here in the UK? Only bigger bolt has finer pitch for JIS.

anyone knows why it is almost like using the bolt to re thread the existing hole? Something is not right...

 

[David]

M8 fine should have a 1mm pitch, a course M8 is 1.25mm

 

[qbartx]

jis standard is the same for uk m8 although you'll be looking at m8 1.0 pitch as David says

 

[Aeroelastic]

Does it matter if it is an import Prado? Will find some fine pitch one...

 

[David]

All will be the same

 

[Higgy]

Right There is Probably the reason yours was missing in the first place....

 

[SteveJB]

Might be the previous owner re tapped for whatever reason when I fitted my bash plate just used off the shelf bolts to get home from metal workers then replaced with some new stainless bolts from screwfix