Thread Identification

[brakemeister]

I am trying to identify the external thread on an EGR fitting in the manifold of a 1999 Ford Expedition. The major diameter of the thread is 1.053 with 13 TPI. The only thread I have been able to find with 13 TPI is a standard 1/2-13.

Any enlightenment would be greatly appreciated.

 

[Hush]

Could it be a pipe thread?

3/4 NSP has a major of 1.034 to 1.024 but with 14 tpi, perhaps your thread count is off by one?

 

[CoryPad]

Could it be metric? All US automobile manufacturers use metric fasteners. Your inch dimensions translate roughly to M27 x 2. You could call a Ford dealer service department and ask.