Identify this bolt ?

Wig

I don't have a thread gauge, I have used my eye
I do have a micrometer

threads are 11.65mm diameter (0.458")
pitch I got 35/21 = 1.6666mm 30/18 = 1.6666mm (15+ tpi)

What is this bolt size please ?

shaun_from_Africa

The nearest I could find in my books is a 7/16 UNC.
That has an outside diameter of 11.12mm and 14 TPI

molerat

Or ASME Special No 30, 11.43mm dia and 16 TPI


My money is on a worn 12mm 1.5mm pitch

Undervalued

molerat wrote: »

Or ASME Special No 30, 11.43mm dia and 16 TPI


My money is on a worn 12mm 1.5mm pitch

Mine too!!

custardy

Wig wrote: »

I don't have a thread gauge, I have used my eye
I do have a micrometer

threads are 11.65mm diameter (0.458")
pitch I got 35/21 = 1.6666mm 30/18 = 1.6666mm (15+ tpi)

What is this bolt size please ?

You can print/check on screen a thread pitch guide

https://www.boltdepot.com/fastener-information/Printable-Tools/US-and-Metric-Thread-Sizes.pdf

Wig

Sorry to be late back here.

I bought a new bit different manufacturer and the screw in there had the same thread. So I was sure it was not non standard 1.666 pitch.

I measured the new one 11.35 mm diameter !
and the threads were the same so I counted them again and realised my earlier mistake. I was counting the thread on 0mm as "1" so I counted 1 too many.

35/20 = 1.75
30/17 = 1.76

It seems to be a very thin diameter M12 with coarse thread.

ohreally

What, if any, markings are on the head?