Anyone know the thread size of Kubota grease fittings?

[Sodo]

1/8 - 28 BSP looks similar to 1/8-27 NPT (USA) but BSP has slightly smaller hole.
A 1/8-27 NPT catches about 1/2 thread in a BSP hole.

Notice the tip of the BSP thread is smaller and the taper is steeper than NPT.

There are tapered thread fittings, straight thread fittings.
I just wanna service my machine, why are there so many different threads for grease fittings?:confused3:

Anyone have a source for an assortment of fittings that fit Kubota?
There's a BSP kit on Amazon for $182, I'd rather spend less but mostly I want to know that they fit Kubota and I'm not about to spend $182 in hopes.
SOMEBODY must know this (please help)!!:drink: I'm not the first guy trying to grease a Kubota.

Note that the Harbor Freight metric kit DOES NOT fit Kubota
Furthermore, also a fairly large percentage of the HF fittings are not shaped properly
- they don't seal
- you can't get any pressure when you need it
- you just make a mess.

 

[jmc]

Thread pitch gages are handy for this and a lot of other issues. Calipers or micrometers will help with straight thread vs tapered, and their major diameters. Then compare your measurements with online thread specs or The Machinery Handbook.

Performance Tool - Thread Pitch Gauge Set SAE/MM (W8655) Fastening - - Amazon.com

Measuring equipment is now so inexpensive compared to back when quality, brand names owned the whole market.

 

[number two]

The Thexton 432 is a handy and inexpensive thread pitch guage set.

Sodo,why not get the most popular fittings instead of an entire set?
1/8 x 28 BSP and M6 x 1.0 should do for the tractor
1/8 x 27 NPT and 1/4 x 28 for the loader.

Good Luck!

 

[YLee Kioti]

This is on flea bay- https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=BSP+grease+fittings&_sacat=0

Gainger - BSPT Grease Fittings and Zerk Fittings - Lubrication - Grainger Industrial Supply

and just for general info - BSP GREASE FITTINGS | BSF GREASE FITTINGS | BSPP GREASE FITTINGS



no doubt BSP fittings are a tad pricey......

 

[JWR]

The last round I had with these things was solved with a bag of assorted zerks of many sizes and threads from Tractor Supply. It is easier to buy a cheap bag & try until one fits than to fool with threading holes and finding specs. For one thing, there is probably no single "standard" size and thread for Kubota. Even if there were, it seems like every implement I own like third party 4-in-One buckets, grapples, mowers, etc. all use different or at best randomly different sizes. So buy a grab bag and forget it.

 

[rScotty]

Could the threads be British??
BSP GREASE FITTINGS | BSF GREASE FITTINGS | BSPP GREASE FITTINGS

Sure could be. There is such a thing as a metric tapered pipe thread spec, but almost nobody in the world uses it. Most metric manufacturers use the British Standard Tapered Thread in applications where you want the fluid sealing ability you get with a tapered thread.
Some British Standard specs are very close to the USA tapered thread specs, but not the same.

And they might not be tapered threads at all. Lots of zerks use a straight thread. And it can be hard to tell the difference.
Plus the zerk fitting hole itself often doesn't go very deep or have very good threads.

Our Kubota M59 TLB came new with both types of tapered zerks as well as metric and USA straight threaded zerk. It also had several angle styles that had to be replaced right from the start so that a standard grease gun would fit them.

Here's a nice chart I found online at GreaseExtensionHoses.com.
rScotty

 

[PILOON]

And then some are simply tapered and pressed in with no threads.

I once got lucky at a gov't sale where a multi compartment parts drawer (like 30/40 bins) was full of assorted zerks.
Straight, 90 +45 degree plus many varied thread sizes. All for $10.00.
Had too have been over 100 zerks in there.
Since more than I ever need in my life I split the find in half and sold that half to a mechanic friend for $10.00
Real win/win. (and he was happy as well)
Now that bin was repurposed to hold my assortment of wood screws since I use screws more often than zerks.

 

[Tractor Seabee]

I am about to find out as I have a broken fitting on my BX that I have to replace before next greasing. !500+ hrs and first one to happen.

Ron

 

[maritimefarmer]

It can be difficult to identify grease fittings. I have made this table to help (or maybe not) from fittings available from manufacturers or suppliers; some may be missing.
Measuring the diameter, TPI or pitch can get you close to proper identification, but due to manufacturing tolerances and type of thread, getting the diameter right may be difficult. And identifying if there is a taper or not can be almost impossible for some.
Maybe it can help someone

diam. in. | diam. mm | fitting designation
0.138  3.5 6-40 UNF
0.190  4.8 10-32 UNF
0.197  5.0 M5x0.8
0.223  5.7 1/4"-28 SAE-LT
0.236  6.0 M6x0.75
0.236  6.0 M6x1
0.250  6.4 1/4"-28 UNF
0.250  6.4 1/4"-26 BSF
0.276  7.0 M7x1
0.313  7.9 5/16"-22 BSF
0.313  7.9 5/16"-24 UNF
0.313  7.9 5/16"-32 UNEF
0.315  8.0 M8x0.75
0.315  8.0 M8x1
0.315  8.0 M8x1.25
0.375  9.5 3/8"-24 UNF
0.375  9.5 3/8"-20 BSF
0.383  9.7 1/8"-28 BSPT
0.383  9.7 1/8"-28 BSPP
0.394 10.0 M10x1
0.394 10.0 M10x1.25
0.394 10.0 M10x1.5
0.405 10.3 1/8"-27 PTF
0.405 10.3 1/8"-27 NPT
0.472 12.0 M12x1
0.472 12.0 M12x1.25
0.472 12.0 M12x1.5
0.472 12.0 M12x1.75
0.500 12.7 1/2"-20 UNF
0.518 13.2 1/4"-19 BSPT
0.518 13.2 1/4"-19 BSPP
0.523 13.3 1/4"-18 PTF
0.551 14.0 M14x1.5
0.623 16.0 M16x1.5
0.656 16.7 3/8"-19 BSPT
0.656 16.7 3/8"-19 BSPP
0.675 17.1 3/8"-18 NPT
0.675 17.1 3/8"-18 PTF
0.820 20.8 1/2"-14 PTF
0.825 21.0 1/2"-14 BSPP
0.840 21.3 1/2"-14 NPT

Grease Fitting Thread Types

M        ISO Metric Taper - thread sealant recommended
S        Metric thread Forming
UNC      Unified National Coarse Thread - thread sealant recommended
UNF      Unified National Fine Thread - thread sealant recommended
UNEF     Unified National Extra Fine Thread - thread sealant recommended
NPT      National Pipe Thread (American National Standard Pipe Thread) - thread sealant recommended
NPTF/PTF PTF, National Pipe Taper Fuel, AKA Dryseal -NPTF threads have the same basic shape but with crest and root heights adjusted for an interference fit, eliminating the spiral leakage path.  Compatible with NPT but leak-free caracteristics are loss.
PTF-SAE Short     NPTF minus 1 thread at small end
PTF-Special short PTF-SAE Short minus 1 thread at large end
PTF-Special extra short PTF-SAE Short minus 2 threads at large end
SAE-LT   Society of Automotive Engineers Lubrication Threads -- Tapered but designed to be installed in a 1/4"-28 straight-thread hole.
NPSM     National Pipe Thread Parallel - thread sealant recommended
BSPT/BSP British Standard Pipe Taper or R-series pipe thread
BSPP	 British Standard Pipe Parallel or G-series pipe thread (previously BSPF and BSPM)
BSF/BSPF British Standard Fine - Parallel

 

[Sodo]

That's awesome! THANKS!

I've copied it and saved to my files.