Got a hole and not sure of the thread any guesses

[Hoofa]

Ok got a hole on the flywheel drilled for the new clutch was told it was unf thread but I am not sure what it is so any guesses based on the following


5/8 unf goes through and pulls out
3/8unf is too big
3/8 unc screws in, seams to fit nice, but then starts to tighten up

The only one I haven't tried is metric, but then it could be metric fine ?


Any guesses chaps ?.

[GasMunkey]

There's a app I use called 'nut sizer'
That will give you the variations with a actual size on screen to line up with

[Quietlybonkers]

GasMunkey said:

There's a app I use called 'nut sizer'
That will give you the variations with a actual size on screen to line up with

....resisting the urge to comment, manfully.........!

[Bassfiend]

GasMunkey said:

There's a app I use called 'nut sizer'
That will give you the variations with a actual size on screen to line up with

I laughed so hard that I farted!

(...and then bought the app even though there's no iPad version. )

Edited by Bassfiend on Monday 21st January 21:54

[Barkychoc]

Are your figures right or am I in beer fog?

UNC
5/8 pulls out
3/8 too big

Wrong way round?

Pretty sure bolts were not metric when I did the V8s, could it be crud in the thread making it tighten?

[SILICONEKID350HP]

What is the hole for ?

[Bassfiend]

SILICONEKID350HP said:

What is the hole for ?

Must ... resist ...

[GasMunkey]

SILICONEKID350HP said:

What is the hole for ?

Does it have hair around it?

[Bassfiend]

GasMunkey said:

SILICONEKID350HP said:

What is the hole for ?

Does it have hair around it?

Why did I resist...?

[Big Al.]

Hoofa said:

Ok got a hole on the flywheel drilled for the new clutch was told it was unf thread but I am not sure what it is so any guesses based on the following


5/8 unf goes through and pulls out
3/8unf is too big
3/8 unc screws in, seams to fit nice, but then starts to tighten up

The only one I haven't tried is metric, but then it could be metric fine ?


Any guesses chaps ?.

I'm assuming you mean 5/16 unf and not 5/8?

It could be a 3/8 BSW, same TPI (16) as UNC, BUT IIRC the BSW has a 55deg thread angle and the UNC has a 60Deg, hence possible reason for it tightening up.

HTH.