1979 Heat exchanger stud size and thread pitch

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Nov 5, 2019 | 11:09 PM

toddk042

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From: St louis, MO

1979 Heat exchanger stud size and thread pitch

I had to cut one of the bolts off the heat exchanger and am having a devil of a time finding a replacement. I thought it was M12x1.00, but I only get a couple turns before it stops.
Any ideas?

Nov 6, 2019 | 12:29 AM

7aull

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From: Arizona

Think these are 1.25 pitch-

Stu A
80GS
AZ

Nov 6, 2019 | 05:36 AM

mazdaverx713b

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They are an M12x1.25

Nov 6, 2019 | 11:04 AM

toddk042

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Hmm, maybe the M12x1.25 bolts I bought are mislabeled and are 1.50 or 1.75. They do look much courser than the nut I cut off.

Nov 6, 2019 | 10:27 PM

toddk042

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It is M12x1.25. The nuts I got were mislabeled.

Nov 7, 2019 | 05:50 AM

mazdaverx713b

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Glad you got it figured out. Mazda never changed their stud sizes on exhaust parts over the years. Always the same size, catalytic converter or heat exchanger.