Help with bolt thread size

[Taylor22]

There's two t30 bolts that hold the armrest in the st at the back. Does anyone know the thread size? I need to get some replacements if anyone can help. 

[Russ]

17 minutes ago, Taylor22 said:

There's two t30 bolts that hold the armrest in the st at the back. Does anyone know the thread size? I need to get some replacements if anyone can help. 

'If' you have a bolt to hand measure across the diameter using a tape measure, they'll be a standard size of something like M6/M8/M10 .... from looking at another forum I think they could be M8 (not having a fiesta mk7 st I can't be 100% sure)

It isn't an ideal method but in the absence of a micrometer or vernier caliper it'll do.

[Taylor22]

They're stuck half way in the armrest at the minute unfortunately

[Luke4efc]

Surely you can back it off enough to get a rule behind it. Torx aren't like head head bolts - where by using the size of the spanner, you can work out the thread size. Torx can be completely random. You can work it roughly, it will either measure 6mm for m6, 8mm for m8 etc. A pair of verniers would be ideal if you can't see behind to read a rule. Pick up a cheap pair from amazon for a tenner.

I would very much doubt that any modern car would use anything other than metric threads nowadays. Well maybe some engine stuff, sump plug etc. comes to mind

[stef123]

depending on what it screws into will dictate what type of thread it has. it is not necessarily a metric thread size such as M6 etc. often torx screw going into plastic or spire clips have a thread which resembles a woodscrew - screws are often measured in 'gauge' 

[Nick_T]

4 hours ago, stef123 said:

depending on what it screws into will dictate what type of thread it has. it is not necessarily a metric thread size such as M6 etc. often torx screw going into plastic or spire clips have a thread which resembles a woodscrew - screws are often measured in 'gauge' 

You are correct, they do resemble wood screws and are self tapping. They have a coarse thread and screw directly into the plastic on the armrest components.   

[Taylor22]

I think they may be a m6x20mm bolt. I've bought the replacement bolt but I'm having the same issue that I can't get the bolt on the left to go more than half way in. One on the right is fine