All, Purchased a cool little winged br*** gas cap for my speedster project and I'm completely stumped by the threads on this thing... The cap has male threads, 16 per inch, threads measure approx. 2.03" O.D. I am 100% sure it is not 2" NPT...won't fit the 2" NPT threads on my fuel tank. Would love to adapt this to a filler tube, but need to know what these threads are.
Wow, a thread thread! (Sorry, couldn't resist) That appears to be a straight thread, not tapered like NPT (National Pipe Tapered). You should be be to get a thread gauge at a good hardware store in order to get the pitch. Maybe a machinist HAMBer can help out, or check the Starrett website.
Pitch is 16 TPI...I just can't find a reference for a 2.03 (2 1/32) x 16 thread size anywhere...comes close to a fine metric thread (M52 x 1.5) but a 1.5mm pitch is 16.9 TPI.
Any idea what it's off? That can often lead you in the right direction. I don't have my Machinery Handbook here but I'm sure someone on here has one on them.
Adapting it to a filler tube would be a no brainer for a good machinist. He would just measure and make the female for that to fit. Even if it isn't a standard diameter as long as he can measure thread pitch and depth with diameter it can easily be done.
Blue One, That's what I was hoping to hear. I'll run it by the local machine shop & see what they say. Thanks!
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