Fuel tap threads

[Bob Purton]

I'm having trouble understanding fuel tap threads. I have a Forge alloy fuel tank with a male thread on the underside as an outlet. The outside diameter of this thread is 5/8" od. A messerschmitt fuel tap scews straight onto it. I'm needing to establish what the thread fitting is because I want to fit a strainght forward outlet spigot to it as I'm going to use an electric solenoid valve instead of a fuel tape. Its probably a BSP thread but I'm unfamiliar with these. Can someone clue me up please?  Thanks.

[super-se7en (Malc Dudley)]

It will be 3/8" BSP (16.7mm dia)
Ebay has all the varieties with elbows, reducers .male to female etc.
Hope this helps.

[Bob Purton]

Thanks Malc. I measured the tpi last night and its 26. Does that fit in with your analysis?

[super-se7en (Malc Dudley)]

I am afraid 3/8" BSP has only 19 teeth per inch.
I can check tomorrow what 26 teeth and 5/8" dia might be if you like.

[Bob Purton]

That would be much appreciated. Thank.

[Rusty Chrome (Malcolm Parker)]

BSC Looks like the only 26tpi 5/8" thread. Some BSP 5/8" compression fittings have 24tpi.

http://www.britishfasteners.com/threads/bsc.html

[Bob Purton]

Thanks for the offers of help on this but I think I have cracked it. Its 16mm x 1mm pitch which turns out to be a recognised fuel tap thread.