after market Norton gas tanks

I have a remake roadster tank of unknown origin which doesn't want to accept the american 5/16 studs. Are these being made with metric threads these days? I am off to the hardware store to buy a couple of metric bolts to see if they work, do not want to run a tap down the hole untill I check. Anyone run into this?
Also, I've seen a few of these tanks from different sources and they all seem to have problems getting the petcock bung in straight

I believe those are what our friends across the pond refer to as CEI.

I would not do anything drastic until one of the familiars pops up with sound info.

jbruney said:

I believe those are what our friends across the pond refer to as CEI.

I would not do anything drastic until one of the familiars pops up with sound info.

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If it is CEI nothing in the hardware store is going to be compatible unless it's a very unusual hardware store. On the pre-Commando bikes with which I am more familiar it was an Imperial thread form but I would have thought the Commando tanks, like much of the rest of the bike, would be UNF. OTOH if the tank was made in Taiwan metric would be likely and if in India/Pakistan metric or anything else.

AFAIK - These should be 5/16 UNF.

I have often screwed in the muffler mounts into commando gas tanks and they are 5/16 24. To answer my own question, I just screwed in a metric bolt easily so the threads are metric. The threaded holes are none too straight, either. The metric studs are $3.39 apiece at the local hardware store

seattle##gs said:

I have often screwed in the muffler mounts into commando gas tanks and they are 5/16 24.

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That is what screws into the Made in India Interstate tank I have...fwiw.

Mine is a mix of everything, and always was.