Which threads where? NPT, BSPT, Metric, Imperial, fine,course etc

[100 td]

I had a search but couldn't find anything so if there is something then please point me in the right (or left) direction!
I'm curious, the question is, where and when (and why) are different threads used on these machines. While I have a set of thread pitch gauges in imperial and metric, it would be nice to have an idea of what and where different threads are used.

I have a B21, with Kubota FEL and backhoe which are made in the USA, this machine is in Australia, so was the hoe/subframe and FEL dealer fit in Australia, was it the whole lot sent from the US, or did the US send the hoe and FEL to Japan for fitment to AUS market equipment?

I'm guessing the following, please advise otherwise.

General assembly bolts for tractor - METRIC COARSE, possibly some METRIC FINE
Engine/transmission, I expect METRIC COARSE and some METRIC FINE
Hydraulics - relief valve gauge port I believe is BSPP or BSPT
Hydraulic valves/hoses on loader and hoe I believe are NPT
All bolts on hoe and FEL are US imperial (UNC I expect) except bolts on the hoe subframe to tractor which are metric.
But I'm wondering where and when the changes are, i.e., are all banjo fitting metric, or are they imperial, are all pump ports BSP, are the lines imperial or metric, fuel pumps etc., etc..
Looking at part numbers give me no clues unfortunately.
So is there a standard, what is it?

 

[Kennyd4110]

Your question has no real answer other than parts are sourced from different suppliers that use different standards in the subassemblies. I just see it as an opportunity to buy more tools

 

[100 td]

While that's good for you guys who will one day go metric, it's a pain when you are already metric.
I'm guessing the change happens at the hydraulic selector valve, I wonder if French or European tractors are all metric, or do they still have BSPP test fittings?

 

[rbargeron]

......where and when (and why) are different threads used.....it would be nice to have an idea of what and where different threads are used........is there a standard, what is it?

My 2 cents: Thread standards were developed for interchangeability - usually within an industry, region, or within the colonial reach of a big industrial power like England or the U.S.. There are many different systems for different uses. American National Coarse, National Fine, ANSI/ASME, Metric, Whitworth, buttress, British standard, straight, tapered, oil & gas, JIC, etc, etc, etc. In today's consumer products for worldwide distribution, metric bolting threads of a few standard pitches are gradually becoming more universal.

Thread pitch decisions (whether coarse or fine) are driven by material strength and production methods. Other codes and standards govern class of fit, sealing performance, tightening torque, on and on.

Guidance on what to use where is established partly by standards, partly by the production experience of manufacturers who've been herding all these design cats for years.

Regarding your Japanese B21 with U.S. attachments your list is pretty close - plus the JIC hydraulic fittings. Metric threads in some diameters are made in several pitches, not just two. Metrics use specific pitch dimensions, not just 'fine' and 'coarse'.

 

[100 td]

Just noted a post by NIW who said the oil pressure sender on a B7100 is BSPT, the interesting thing about this is the use of British threads on a Japanese engine in the USA.
I'm guessing my hoses would be JIC, but could be SAE 45 degree flare.
Metric threads do come in different pitches, but are generally categorized into Coarse and Fine threads for general use sizes. Fine threads may be one of around three different pitches than the coarse in the same size and up to seven or more in the larger sizes. I have a fair set of Coarse thread taps, and the odd Fine thread tap.
http://www.newmantools.com/tech/threadmf.htm
http://www.newmantools.com/tech/threadm.htm

 

[100 td]

Getting away from it is the old spark plug with a 14mm thread x 1.25 pitch (Fine), with a 3/4" reach and a 13/16" drive!

 

[CaveCreekRay]

In 1983 I bought a Camaro Z-28. The car came with half metric and half standard nuts and bolts. Is GM still doing that? Talk about a PAIN.

Gee.. or was it my '78 Z-28? Can't remember....

 

[Russell King]

Most of the bolts on the tractor itself will be extra fine pitch metric. Kubota seems to love M12x1.25 pitch bolts


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[Tooljunkie]

Just did an engine swap on an 09 chevy 5.3. No imperial hardware. I used less tools to replace engine than i used to replace a water pump in a cadillac.

Rarely will you find sae 45 degree fittings in a hydraulic system. Mostly in air and fuel handling.

Its mind boggling to imagine all the types of hydraulic fittings. They all have their purpose. But i cant understand the use of british pipe threads on a japanese made machine.

 

[GeoHorn]

Just did an engine swap on an 09 chevy 5.3. No imperial hardware. I used less tools to replace engine than i used to replace a water pump in a cadillac.

Rarely will you find sae 45 degree fittings in a hydraulic system. Mostly in air and fuel handling.

Its mind boggling to imagine all the types of hydraulic fittings. They all have their purpose. But i cant understand the use of british pipe threads on a japanese made machine.

Is it stranger than John Deere still claiming to be an American machine?

 

[TheOldHokie]

I had a search but couldn't find anything so if there is something then please point me in the right (or left) direction!
I'm curious, the question is, where and when (and why) are different threads used on these machines. While I have a set of thread pitch gauges in imperial and metric, it would be nice to have an idea of what and where different threads are used.

I have a B21, with Kubota FEL and backhoe which are made in the USA, this machine is in Australia, so was the hoe/subframe and FEL dealer fit in Australia, was it the whole lot sent from the US, or did the US send the hoe and FEL to Japan for fitment to AUS market equipment?

I'm guessing the following, please advise otherwise.

General assembly bolts for tractor - METRIC COARSE, possibly some METRIC FINE
Engine/transmission, I expect METRIC COARSE and some METRIC FINE
Hydraulics - relief valve gauge port I believe is BSPP or BSPT
Hydraulic valves/hoses on loader and hoe I believe are NPT
All bolts on hoe and FEL are US imperial (UNC I expect) except bolts on the hoe subframe to tractor which are metric.
But I'm wondering where and when the changes are, i.e., are all banjo fitting metric, or are they imperial, are all pump ports BSP, are the lines imperial or metric, fuel pumps etc., etc..
Looking at part numbers give me no clues unfortunately.
So is there a standard, what is it?

Just did an engine swap on an 09 chevy 5.3. No imperial hardware. I used less tools to replace engine than i used to replace a water pump in a cadillac.

Rarely will you find sae 45 degree fittings in a hydraulic system. Mostly in air and fuel handling.

Its mind boggling to imagine all the types of hydraulic fittings. They all have their purpose. But i cant understand the use of british pipe threads on a japanese made machine.

Pretty simple - part of the legacy of British empire rule in Asia.

Dan

 

[torch]

Just to confuse the issue further: there is often no single metric "fine" thread. While there is generally one standard coarse thread, there can be multiple definitions of "fine" depending where in the world one is standing. For example, M10 comes in four different pitches: 1.5mm (most common), 1.25mm (common in Europe), 1mm (common in Japan) and even 0.75mm.

 

[GreensvilleJay]

What I detest are 'hybrids' !!! Anything, EVERYTHING that's got a MIX of so called 'standards'. Some Metric, some Imperial, the rest are a guessing game...
Why ? Cause the manufacturer CEO 's wife's second cousin needed a job, so some oddball part had to be custom made by HIM.......
never ever understood the NEED for 5.5mm either, 5 OR 6.... dang, next week it'll be 5.25........