Kubota RCR48 mower deck spindle nut thread/size?

[998cc]

Good day all.
I am hoping someone has an answer. My RCR48 mower deck needed new blades. The nuts on the spindles were very difficult to remove. One came off with an impact driver; the remaining two had to be removed by grinding them down and splitting them. The spindle threads are good.

I ordered 18mm nuts which are too small. I then ordered the next larger (20mm) nuts which easily thread on the spindle, but these are sloppy loose on the spindle threads. Can anyone confirm what this thread is?

Thanks.
Russ

 

[998cc]

I found a fine-thread M19 spindle nut from NAPA auto parts. I'll try that.

 

[998cc]

Folks, I am back again looking for (3) M19, fine thread nuts. The NAPA nuts are not available.

I think the OEM Kubota nuts (unavailable) are M19X1.0mm. I found stainless nuts on Ebay but assume they are too soft for fastening mower blades. It seems M19X1 clamping nuts are available for CNC mill chucks; however, these are more tubular and are certainly not up to the task. My last plea for help.
Thanks
Russ

 

[SteveS42240]

Try Amazon for your mower parts. I have bought several parts from them for my machines.

 

[Beaver Cove Deere]

McMaster Carr

 

[998cc]

McMaster Carr

That was the first place I looked. No luck. Usually, they have anything and everything with overnight delivery.

 

[998cc]

Try Amazon for your mower parts. I have bought several parts from them for my machines.

Nothing found on Amazon. Like other suppliers, they step from M18 to M20. It seems odd that Kubota would specify a nut that is so difficult to source.

 

[arto98607]

How about measuring the thread outside diameter and the thread pitch, instead of trying to guess it?

Many Kubota decks are US made and may not have metric threads - at least my 72" deck does not.

 

[998cc]

Sometimes I wonder why I overlook the obvious. ;-) The threaded stud diameter measures .750", and the thread measures "1.5" on the metric thread gauge. It also measures 16 TPI, which does correspond to a 3/4X16 US thread. 19mm is .748 which is close to 3/4" (.750"), so the saga may continue.

I have decided to try a US 3/4"X16 Grade 8 nut to see if it fits. McMaster Carr.
Thank you arto98607

Russ
Kubota B7100HST
1973 Norton Commando
1953 Vincent Black Shadow
Ham Radio Junkie

 

[998cc]

To wrap this up, the spindle thread is indeed 3/4"X16TPI. I confirmed by chasing the thread with a 3/4X16 die. It is a large die, 2-1/2" O.D., which made it possible to chase the thread by hand using the die alone.

Thanks to all who responded.
Russ