If a 5/16 is too big I would just drill and tap the hole to that size.  God only knows what Ford used.  IMO the likelihood of finding the correct one is about zero. 

Yeah, metric threads can come in 1.0, 1.25, and 1.50, and possibly other thread pitches I've never seen.  This can be a real nightmare trying to match things up, especially those made in the PRC (as I posted on another thread).  Sometimes the pitch needed isn't even commonly available.  I installed a turbo once that had bolt holes taped for M10x1.5, but they were supposed to be tapped for M10x1.0.  This made it impossible to reuse the factory studs AND of course it didn't come with new studs.  I ended up making studs threaded for M10x1.50 on one end and M10x1.0 on the other from some bolts I cut down and ran a die down the shanks.  All told this took me about a half a day, which was longer than it took to remove the old turbo and install the new one!  So yeah, don't make yourself crazy over it.  There's enough that'll do that baked into life already. 

I solved it, and hereby nominate myself for the "Moron of the Month" award.  I picked around in another of my caches and found a bolt that fits it perfectly.  Yup, 5/16-18.  I guess I need to do some additional sorting in one of my nut bins ... or maybe just dive in and enjoy the company.

Argh!

Last edited by John Ha (8/02/2024 1:54 PM)

BobE wrote:

KeithP wrote:

BobE wrote:

If it is a metric thread, there varous sizes of the thread pitch sizes, it could be a 1 or 1.5 pitch. One really needs a thread pitch gauge to determine which it is.
If this is a for mounting, I'd go with TKO's suggestion, and don't make yourself crazy.  

Do you think Ford used any metric fasteners in 1965?

I don't believe metric threads were used in any great quantity by the American manufactures at that time.  However, if it were less expensive to use certain parts from overseas ... 
As TKO stated, I've had issues with oddball metric threads that don't seem to conform to the 'standard' thread types being sold (like on Bolt Depot). 
It appears it is not an issue for John Ha as he found it is a 5/16-18 thread. 
 

That was my thought too.  If Ford built it in house or used an American supplier like say Bendix I would say there is zero chance anything metric was used.  But, Ford did have a relationship with Girling, which was a UK based suppler for brake parts so you never know for sure. 
 

I don't know why I made that so hard other than apparently having some metric bolts in the little drawer that is supposed to have 5/16 coarse bolts in it.  I'd thought at one time that Kelsey-Hayes might have been British in 1965 but dispelled that the other day with a quick internet search.  I couldn't explain why something made in 1965 would have a metric bolt either, other than reading somewhere that it was a "special" bolt.

I guess it was just my turn to be an idiot.  Comes around once in a while.  Nothin' to do about it but grin and bear it.  Gotta say though, it's nice to have some polite fellows who answer kinda silly questions with decorum and tact.  Thank you!
 

I have a tap and die set in my tool cabinet.  Never even thought about using that.  My brain obviously wasn't functioning worth a pooh-doo that day.  Oh well, what's another "Mom!  Dad did it again!"