Ewarts 342560 fuel taps

[Brucie64]

I have a confession!

I was brought up on japanese bikes and as such don't have a scoobies about Whitworth or indeed BSP sizes, I have a tank that I would like at some stage to connect to my Spitfire Scrambler via some ewarts tank taps.

Can anyone hazard a guess as to what size threaded gas nut (and associated spigot) will fit these ewarts tank taps?

The standard size termination i.e. 1/4 gland nut (14/042) and ancorn nut (67-8060) are incorrect. I have a sneaky suspicion that it maybe 7/16" but would like any expert opinions before I fork out for yet more nuts and bolts in a vain attempt to connect my tank to the carb!

[A10Boy]

They are usually a 1/4 BSP thread.

[Triton Thrasher]

Brucie-64
Are you confused because 1/4" pipe thread is about 7/16" across?

The 1/4" refers to pipe bore.

[Brucie64]

Now I am even more confused.

Here's an idea, if I were to source a tap & die set  could find the right thread size by using this right?, however would I need a BSW or a BSP tap & die set?

Or should I just check em in the bin and get a new set with documented thread sizes 

[Triton Thrasher]

Take the tap to a plumbers' supplier. They still use gas fittings in those sizes.

[A10Boy]

You will probably find everything you are looking for on good old ebay. There are always loads of fittings there. Search in Motorcycle parts and accessories.

[groily]

And if you want all the data on almost every thread you can think of, go to www.mdmetric.com/thddata.htm or other similar places. That's my personal favourite. It's very anoraky stuff but very helpful, and gracious of our transatlantic friends to have catered so well for metric threads, British imperial and British plumbing. I don't know a better site, but gave up looking when I came across them anyway.

[Brucie64]

Hey, Many thanks for everyone's help, rushed home especially early from work today to try and get to the local plumbers outlet as suggested. It closed just as I entered the carpark. Sods Law!