# Banjo Bolt - Help!



## Snafu51 (Nov 18, 2016)

I need help locating a banjo bolt (joint bolt) for the hydraulic pump on my B7200. The original engine has been replaced so I think the hydraulic pump is not original to the tractor. The listed bolt from Kubota for the B7200 is too short. The bolt I have is approximately 2" long bottom of thread to top of bolt with a 1/2" pipe thread. The thread length is approximately 1/2". The bolt head fits a 1 1/8" wrench. Of course the tractor is down until I find a replacement bolt. I've been searching about a month. Any help at all would be appreciated.


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## jhngardner367 (Apr 5, 2011)

Welcome to the forum,Snafu51 !
What model,and make is the pump? 
Is there a tag on it?
If so,post it,and we may be able to get a sight that stocks one.


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## Aircommuter (Jun 12, 2016)

I don't see how a pipe thread could be used on a banjo bolt, as it would never tighten up on the washers. Can you post a photo and measure it from the threaded tip to the underside of the head, and re-check that thread diameter and pitch, also the diameter of the portion just below the head.


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## jhngardner367 (Apr 5, 2011)

Aircommuter said:


> I don't see how a pipe thread could be used on a banjo bolt, as it would never tighten up on the washers. Can you post a photo and measure it from the threaded tip to the underside of the head, and re-check that thread diameter and pitch, also the diameter of the portion just below the head.


There are both straight pipe threads, and tapered pipe threads. 
Tapered threads are the common type used in plumbing,gas,etc. piping.
Straight pipe threads are used in hydraulic systems,brake systems ,etc. among them,the banjo bolts.


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## Aircommuter (Jun 12, 2016)

The threads used in hydraulic systems for clamping purposes like banjo bolts are SAE threads not pipe threads. I have been in the hydraulic and equipment repair business for over 50 years. You should go to a website that gives the thread pitches used on banjo bolts and "O" ring fittings in hydraulic fittings and you will see they are not the same pitch as pipe threads, also tapered pipe threads are used in hydraulic systems.
Go to www.surpluscenter.com and study the fittings, then look at the thread pitches and compare.


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## Snafu51 (Nov 18, 2016)

Thanks for the replies. I believe the thread is National Pipe Straight Mechanical (NPSM) vs National Pipe Thread (NPT). I'll have to pull the pump to find any numbers.


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## Aircommuter (Jun 12, 2016)

Can you measure the pitch? Npsm has the same pictch. Since this machine is modified it could also have ermeto, DIN, there is also bsp straight but in 1/2" they are the same pitch, in tapered they are different taper angles. Pitch is the key to the correct banjo bolt, I have a lot choices here in my stock, most are used but good, they are also pretty easy to make on the lathe.


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## Snafu51 (Nov 18, 2016)

I'll have to dig through my box for my pitch gauge. It does screw into a 1/2" pipe fitting but is straight. I'll try to figure out how to post a picture.


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## Snafu51 (Nov 18, 2016)

Pics of bolt and one of the crush washers.


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## jhngardner367 (Apr 5, 2011)

This is what I was going by:
http://www.usplastic.com/knowledgebase/article.aspx?contentkey=998


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## Aircommuter (Jun 12, 2016)

That is all correct, but it doesn't say what the common uses are. Straight pipe fittings are an old use for clamping puposes because they don't develop as much clamping force as SAE. Tapered pipe is very common in hydraulics, but SAE and JIC are more common.
I will look and see if I have a bolt that size, it looks coarse compared to SAE, it should be about
.840 diameter if it is 1/2" pipe.


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## Snafu51 (Nov 18, 2016)

Yes, the diameter is about .840. Maybe just a hair under on the ID of the washer.


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## Aircommuter (Jun 12, 2016)

I went through a box of 100+ banjo bolts but not one has straight threads that coarse. I think making one might be the way out, sorry I couldn't help.


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## Snafu51 (Nov 18, 2016)

Thanks for making the effort.


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## FredM (Nov 18, 2015)

don't you have a hydraulic shop close by??.


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## Snafu51 (Nov 18, 2016)

There are hydraulic shops nearby but they mostly cater to the oil and gas industry. As Aircommuter said I'm probably going to have to find a machine shop.


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## Aircommuter (Jun 12, 2016)

I usually make them from a bolt that has the correct threads on it already, in the case of that one you could start with a 7/8 bolt , turn it down to .840 thread it and drill it.


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## Snafu51 (Nov 18, 2016)

Thanks for the advice.


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## oldtom (Oct 23, 2010)

Aircommuter said:


> The threads used in hydraulic systems for clamping purposes like banjo bolts are SAE threads not pipe threads. I have been in the hydraulic and equipment repair business for over 50 years. You should go to a website that gives the thread pitches used on banjo bolts and "O" ring fittings in hydraulic fittings and you will see they are not the same pitch as pipe threads, also tapered pipe threads are used in hydraulic systems.
> Go to www.surpluscenter.com and study the fittings, then look at the thread pitches and compare.


this is on a Kobota it be metric.









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