Compressor air inlet thread

[Rowan Sylvester-Bradley]

I have a compressor branded Warrior, made in China. The air inlet thread in the head does not seem to fit any air filter that I can find, so I'm trying to make an adapter. What is the thread in the head likely to be? It is a bit smaller than 3/8 BSP. It looks about 14mm dia inside the threads.

Thank you - Rowan

 

[Rowan Sylvester-Bradley]

The thread pitch seems to be about 1.5mm.

 

[julianf]

Could be npt. Possibly metric, but my money would be on npt.

 

[Turbo]

They are usually 1/2" bsp but goodness knows what a Chinese one will use.

Anything smaller than that would be restrictive. Is there enough metal to drill and tap it out to a common size thread?