anybody know what the thread is on the 4 screws that hold the heater/radio panel to the dash?

Thanks,

Ken

I wish I knew, but if I remember correctly it was a fine pitch like 10/32

It seems I do remember that they were the only screws like that in the whole car- PITA.

4mm x 0.75. Slight chance they are 5 x .8 can't check till I get home. One or the other for sure.

I just checked mine on my '70 and three of them are M4 x 0.7mm with a Phillips head and strangely one is a No. 8-32UNC with a slotted head.

Mike

Just an update, when I reinstalled the screws the M4 x 0.7mm did feel like a better fit.

Edited August 2, 201311 yr by CanTechZ

the m4x0.7 fit, but they're a squeeze ( using socket head screws because they're black ) the 8-32 is definitely not right. think these may be the same thread as the coat hangar hooks, whatever that might be......

Yup, I was dreaming about the .75 pitch. 4 x 0.7 is the correct pitch. Definitely not 8-32 though

This is probably not helping you now, but could be handy later when trying to identify bolt sizes in your Z.

I think Datsun almost always used what is known now as the ISO standard for screws and bolts.

The ISO thread standard has been around more or less since 1966 and is made up several documents.

These are the most used:

ISO 68-1 Profile (Thread cross section)

ISO 261 General plan (Diameter and pitch combinations)

ISO 965-1 General Tollerances

ANSI and SAE worked with ISO in the early seventies and ASME jointed in later. The more you read standards the more confusing it gets.

ASME has a good document you can use to find threads and I think it would be exceptional if you found a thread in a Datsun that is not mentioned. With exception of left hand threads which is another standard.

http://www.cmpubolt.com/docs/B1.13M-2005.pdf. (see document page 9 to11)

Chas