Thread sizes and reducers/adaptors

[rastik86]

G'day. I tried to outsmart myself and rang the mob who I ordered my Xforce 3" exhaust on eBay and asked them to weld a bung in the dump pipe knowing I was going to install an EGT gauge soon. I chose Autometer Cobalt gauges, did my research and clearly asked them for a 1/8" NPT sized fitting for the 1/8" NPT pit that comes with the gauge for the temp probe. They must have decided that I'd get what I was given and gave me what I was given.


Now... The bung has a M12 x 1.25 plug/bolt in it which is slightly loose when you hand tighten it in but nips up tight with a socket. I tried a M12 x 1.5 to 1/8" NPT and it felt as if it would keep turning and strip the thread.

So does anyone know there thread sizes around M12 and equivalent imperial measures to try and solve this problem so I can hunt around for a reducer/adaptor to temp probe pot?

I know it's sort of like posting "How long is a piece of string?", but if I can narrow down to a handful of thread sizes that people think are similar I can grab bolts in those sizes to try instead of buying 300 different adaptors.

Cheers in advance

 

[Aussie Frontier]

How about buying a brass bung the right size for the weld in bung in the pipe. Then you can buy a tap n drill and make a perfect fit

 

[rabbit-chop]

If the bung is 12x1.25 and the probe is 1/8npt then thats what adapter you need. My advice would be save some running around and weld the 12x1.5 adapter in... provided the probe actually screws into it of course!

or just plug it and put another one in. Cheaper than buying another adapter.http://www.ebay.com.au/itm/1-8-NPT-..._Parts_Accessories&hash=item257e5640eb&_uhb=1

 

[rastik86]

How about buying a brass bung the right size for the weld in bung in the pipe. Then you can buy a tap n drill and make a perfect fit

I'm not sure the right size of the weld in bung, but that's the idea. like I said it has a m12 x1.25 bolt but it feels loose. I'll go to a nut and bolt joint with the bolt and get them to find bolts similar and try and find the right exact fit I guess

 

[rastik86]

If the bung is 12x1.25 and the probe is 1/8npt then thats what adapter you need. My advice would be save some running around and weld the 12x1.5 adapter in... provided the probe actually screws into it of course! or just plug it and put another one in. Cheaper than buying another adapter.http://www.ebay.com.au/itm/1-8-NPT-steel-weld-on-bung-insert-theaded-female-/161033371883?pt=AU_Car_Parts_Accessories&hash=item257e5640eb&_uhb=1

I didn't think the bolt should have as much wiggle in the thread as it has, hence thinking it may be a similar but different size.

Can you weld a bung on top of a bung? I have never welded, don't own one and am not confident in welding one in. Would you have to take the dump pipe out, cut the existing bung off and drill and weld a new one in?

Sorry stupid iPhone auto spell correct

 

[rabbit-chop]

If its in the dump pipe and the dump pipe unbolts fairly easily then i would probably remove it, cross thread or grind and insert the adapter and weld it, but thats just me., other option is to drill and tap a 1/8 npt threaded hole in the pipe if its thick enough, but for the price of tap and bit you can just buy the correct adapter and screw it in.http://www.ebay.com.au/itm/Sensor-A..._Parts_Accessories&hash=item418191d3bb&_uhb=1

but if you are unsure of the thread size then yeah, maybe visit local bolt shop or ask x-rort what they used, but generally if a bolt screws in then its the right size unless its ridiculously loose or something.

 

[Aussie Frontier]

Was just thinking it would be unlikely they had a metric bung but they could have used a NPT bung. Try a 1/4" NPT bung or similar ,thats a straight thread or 1/4" BPT which is a tapered thread

 

[d22dave]

Ring them up and ask the exhaust place what size they used

 

[rastik86]

Ring them up and ask the exhaust place what size they used

I will tomorrow but, they assured me they would weld in a 1/8 NPT fitting first when I rang and asked them to and second when they rang back to confirm they could and would do it before they shipped it, and I even wrote it in the notes section upon payment via PayPal. So my confidence in them telling me what they used is 3/4 and 5/8 of FA, or to them M12 of FA

 

[rastik86]

Was just thinking it would be unlikely they had a metric bung but they could have used a NPT bung. Try a 1/4" NPT bung or similar ,thats a straight thread or 1/4" BPT which is a tapered thread

Cheers, I'll try both

 

[rastik86]

If its in the dump pipe and the dump pipe unbolts fairly easily then i would probably remove it, cross thread or grind and insert the adapter and weld it, but thats just me., other option is to drill and tap a 1/8 npt threaded hole in the pipe if its thick enough, but for the price of tap and bit you can just buy the correct adapter and screw it in.http://www.ebay.com.au/itm/Sensor-Adapter-Oil-Water-Boost-Temp-M12x1-25-To-1-8-NPT-/281346692027?pt=AU_Car_Parts_Accessories&hash=item418191d3bb&_uhb=1 but if you are unsure of the thread size then yeah, maybe visit local bolt shop or ask x-rort what they used, but generally if a bolt screws in then its the right size unless its ridiculously loose or something.

Cheers. I just thought it should be a little more of a snug fit when screwing it in by hand, but you can literally wiggle it around as you screw it in and I only just nipped it up with a socket as I don't want to root the thread. Whereas, as I said the adaptor with the M12 x 1.5 thread felt like it would just keep going until the thread was rooted.

Thanks for your help, I'll grab one of those suckers if Aussie Frontier's suggestions don't pan out.

Worst comes to worst I'll get an exhaust joint to sus it out. Just didn't want to go down the path of having the exhaust and turbo I just had put in played around with for this lol

Thanks for everyone's help, will post results in case any one else ends up with the same dilemma

 

[rabbit-chop]

Ok, it might be some kind of pipe thread then. best call the place you bought it from.

 

[bods]

I reckon 1/4" might be the go. I think you'll find that's similar to m12, and you should be able to get a steel reducer from 1/4 - 3/8".... If you can try one first that would be your best bet, but at that size, bsp and npt are so close that one will screw into another with no issues....

 

[Dion]

Sounds like the m12x1.25 might be for a small lambda sensor (whereas the big ones are m18), they're metric because Bosch was the leading OEM supplier of EFI equipment when it was growing and they're German.

They've certainly made a special effort and gone full retard for you, drilling and tapping a blanking bolt would my approach but without access to a 1/8 npt tap buying an adaptor from eBay might be the best way forward.

 

[rastik86]

They've certainly made a special effort and gone full retard for you,

And then some!

 

[d22dave]

I will tomorrow but, they assured me they would weld in a 1/8 NPT fitting first when I rang and asked them to and second when they rang back to confirm they could and would do it before they shipped it, and I even wrote it in the notes section upon payment via PayPal. So my confidence in them telling me what they used is 3/4 and 5/8 of FA, or to them M12 of FA

Fair call. I picked up my own bits from enzed and gave them to the bloke to weld on my dump pipe. If its wrong its my fault

 

[rastik86]

Fair call. I picked up my own bits from enzed and gave them to the bloke to weld on my dump pipe. If its wrong its my fault

In hindsight I should have waited for delivery and done something similar... But that's the thing about hindsight.

I been flat out at work and I'm working in a building where the client doesn't allow the use of mobile phones, so couldn't ring today. Hopefully have it all sorted by weeks end.

 

[d22dave]

We've all been there with hindsight