identify thread size

Hello

does anyone have any idea what the thread might be on these PANEL-MOUNT-DC-PLUG-SOCKET-JACK
the OD is 11.65mm unlikely to be metric I'm thinking - if they sourced from America could they me something not metric ?
because of the depth of material their going into i need to tap the hole

any help appreciated

Sounds like M12.

You will need a thread gauge, available at most hardware stores.

jremington
your a luck man if you still have hardware stores, or at least ones that sell useful stuff like thread gauges, ours no longer sell such exotics - though theres always ebay

though i do have a set i picked up of our local market recently, purchased as a reminder of my engineering days, not that i thought at the time they might be useful

the pitch is close to 27 threads per inch - would have been better if the gauge was metric

Shpaget
the thread OD is .35 less than 12 mm, i would have expected a 12mm thread to have been closer to size

as I'll have to buy the tap I'd rather know what I'm after

You could always just ask the seller....

the ONLY want to know is to measure.
if you buy from a distributor like Mouser or DigiKey, you get brand name with data sheet.
when you save the $$$ by getting from e-bay you have no control if they are the same from shipment to shipment.

Normally these items are not standard (coarse) metric threads. A M12 thread has a pitch of 1,75mm, that would be 14,5tpi. A fairly common pith of fine metric threads is 1mm which translates to 25,4 tpi. An if you measure OD of threads the measurement is often a bit less than the nominal one. So a good guess would be M12x1

dave-in-nj:
http://www.adafruit.com/datasheets/KC-301339.pdf

the ONLY want to know is to measure.
if you buy from a distributor like Mouser or DigiKey, you get brand name with data sheet.
when you save the $$$ by getting from e-bay you have no control if they are the same from shipment to shipment.

True about getting proper data sheet but the one you linked to has a M12.5x1.0 thread so is not likely to fit in an 12mm drill hole.
From China I'm inclined to think it's metric.

jremington,
your a luck man if you still have hardware stores, or at least ones that sell useful stuff like thread gauges, ours no longer sell such exotics

I live in a town of about 100,000 people, and I know of at least seven stores that sell thread gauges.

But then, in the U.S.A., one of only three countries in the entire world that refuse to adopt the metric system (the other two are small nations in Africa), one needs such tools! Everyone who works with mechanical equipment has to switch between both systems many times each day, at who knows what cost.

I would expect to see plastic threads on Made in PRC stuff to be sub standard. Take an M12 screw and try to screw it on. If it fits ok, you have your answer.

jremington:
Everyone who works with mechanical equipment has to switch between both systems many times each day, at who knows what cost.

In case of Mars Climate Orbiter - roughly half a billion $.

I think you'll find it's a 7/16 unf thread.

dave-in-nj:
when you save the $$$ by getting from e-bay you have no control if they are the same from shipment to shipment.

Some eBayers look to sell consistent product. The listing referred to seems to, so the OP really should ask the seller.

Riva:
True about getting proper data sheet but the one you linked to has a M12.5x1.0 thread so is not likely to fit in an 12mm drill hole.
From China I'm inclined to think it's metric.

my point is that you can buy known goods with known dimensions.

it is clear that the link is not the same as the e-bay special.

I'd still put money on it being 7/16 unf.

ChilliTronix:
Some eBayers look to sell consistent product. The listing referred to seems to, so the OP really should ask the seller.

I agree on both accounts, but if you are setting up an assembly that will be made to manufacture, you cannot guarantee that parts will always be consistent unless you buy from a source with a manufactures part number.

as to the supplier, you are correct, but as their supplies dry up or change, they will no longer sell the old part, but will sell the new. either way, not something one can count on.

KenF:
I'd still put money on it being 7/16 unf.

not sure, but I would think that the only place 7/16 would be used would be in the states.

not sure if they are Made in America.

my wager is that they are made somewhere else.

dave-in-nj:
not sure, but I would think that the only place 7/16 would be used would be in the states.

not sure if they are Made in America.

my wager is that they are made somewhere else.

My wager is ALSO that they're made elsewhere. I still say it's 7/16 unf. It used to be pretty standard in the UK and throughout the British Empire for pipework AND panel mountings (switches, warning lamps, sockets). The 7/16 unf thread is ideal for the job so it continues to be employed for these things.

7/16 UNF has 20tpi, not consistent with the 27 mentioned earlier

nilton61:
7/16 UNF has 20tpi, not consistent with the 27 mentioned earlier

Hmm didn't spot that, could possibly be 7/16 unef (that would be 28)

Why not buy one M12 nut and try it on the thread?
Some hardware shops will even let you try before you buy.
And one nut will hardly cost you a fortune, even if it doesn't fit.