Yanmar Grease Fittings

[clemsonfor]

On a Yanmar it is probably BSPT thread. I don't know why but I only see BSPT threads on Japanese stuff. The 2 most common tapered pipe threads are NPT and BSPT. On a Zerk fitting if the thread is a tapered pipe thread it is most likely gonna be a 1/8 pipe thread. NPT, Natonal Pipe Tapered Thread, which is what you would see in America, will have a 60 degree thread form and for 1/8 pipe will have 27 threads per inch. BSPT, British Standard Pipe Tapered, will have a 55 degree thread form and 28 threads per inch. As you can see the threads are very close. For a Zerk fitting I don't really think using a BSPT in an NPT hole or the reverse will make any difference. I have done it more than once. My reasoning goes like this: The threads on Zerk fittings are usually quite soft or quite hard. So the fitting will either conform to the tapped hole or will make the tapped hole conform to the fitting. In either case you end up with a fitting that will not let grease out or water in. Of course it is best to use the proper thread. But if you can't find the proper thread then use some thread dope or Teflon tape and install the Zerk. This is just my opinion and is worth what you paid. Even though I have been doing this for years it is technically bad practice and I only do this for Zerks. I understand that it is bad practice and if I was doing a job for a customer I would insist on using the proper thread. But for my stuff I have interchanged threads and never have had a problem. I don't really like doing it but sometimes I have had to make do.
Eric

I was going to say you could cut new threads for the next bigger one or jam one in. It's not correct but all your doing is trying to get grease in there .

 

[ponytug]

The three issues that I have with changing the threads for grease fittings are that I need to have a blind, or bottoming, tap to be effective, I am not a fan of trying to change threads in an existing hole for strength reasons, and I need some way to ensure that I don't let metal chips from the tap get into the bearings. It is the latter one that keeps me from rethreading blind bearing fittings if I can't completely disassemble them. I may be too cautious, but there it is.

That said, I would love to have a set of thread checkers that could thread into BSPT, metric, and SAE threads. I used to help maintain a machine with Whitworth fittings and threads. Nightmare finding parts in the US. I find myself with a micrometer trying to measure fittings, then checking threads, and then going back thinking "that can't be right". Kubota apparently has some fitting threads used only on their machines.

Anyone have a good way of measuring the angle on flare fittings other than by eye? I ran into some challenges awhile back on a new to me hydraulic attachment, and found myself looking at new to me types of flare fittings that weren't SAE/Metric/BSPT.

All the best,

Peter

 

[oldtimer 66]

Here's my guess./ From the photograph it looks like the thread OD is some where between .31 and .38. I found this on the internet,

JIS Tapered Pipe Thread Type – PT​

PT thread type is identical and interchangeable with BSPT thread type. However, since the male PT thread does not have a 30-degree flare, it will not mate with the BSPP female swivel with conical seat. Also, we recommended using thread sealant with PT threads to ensure a leak-free seal.

Dash Size (Nominal Size)	Thread Pitch	Male Thread O.D. mm	Male Thread O.D. inches	Female Thread I.D. mm	Female Thread I.D. inches
-02 (1/8)	28	9.4	0.37	8.1	0.32

 

[etpm]

I didn't know that JIS tapered pipe thread is identical to BSPT thread. No wonder I saw BSPT threads on Japanese stuff, it is really JIS threads that I saw. Thanks.
Eric

 

[careyo63]

Worked daily on multiple country's Equipment German,Russian,Japaneese and USA. It was crazy late 70's early 80's for us. I had to look up. JIS JIC. I'm Cert. CRS......

JIS vs JIC fitting standards - Knowledge - Yuyao Jiayuan Hydraulic Fitting Factory

JIS vs JIC fitting standards

www.jiayuanfitting.com

 

[city_slicker]

I dont know how to do a search on here. Someone has probably already addressed this, but I cant seem to figure out what size my zerks are.
I tried metric and they dont fit. SAE either, although 1/8" NPT seems close.
What the heck am I dealing with here?

Hi John,
You may have already found the answer, but I too fought with these grease fitting replacements on my 2015 SA424 FEL. Long story short, they are M8x0.75. I used the LockNLube thread tester. After finding out they are more expensive to source, I tapped them all to M8x1.
Much more common, in stock, and cheaper. Hope this helps everyone.

 

[careyo63]

Lock and lube the way to go! Then you can get it out.

 

[Razzmatazz]

SFGF-6 GREASE FITTING

Grease fitting Repl. 194151-11480 (1)

www.southernfarmequipmentimports.com

 

[Smokeydog]

Finally bought a gauge from Zoro on sale. Lot Japanese stuff uses BSPT.

 

[ponytug]

Looks nice!