Bolt Size Help

[nwut05]

Boy, this has turned into a pissin' match.

Has the OP tried sticking a thread pitch gauge in the hole to check the pitch?
That would seem to be the obvious first step to me.

Hey I would if I had one, I'm by no means a mechanic (that should be obvious by now lol ) and the tap and die set is what I have and it's missing some, or, maybe a lot of what used to have in the set. My guess is that if it had a pitch gauge it got pitched somewhere at one time or another over the years and nobody was batting . I do thank you for the response, but i just don't have a pitch gauge here at the farm.

 

[TMGT]

Have you tried an M16x1.0 extra fine thread bolt yet?
I've run into this multiple times where Kubota will use extra fine threaded bolts, it's a pain to find them and usually requires me to special order (local fastenal doesn't stock a great selection of metric).

 

[KWentling]

I was looking at the wrong holes now that I see a picture with some surrounding features. I apologize for misleading you. I did not use those holes so I've not had a bolt in them. I can confirm that a 14 slides right in them. I'm pretty sure they will be 16x1.5. Definetly will be a metric fine thread.


The loader mounts are cast steel. If you see factory welding on them, that is a good indication.

 

[KWentling]

I brought a 16x1.5 tap home from work and that is the bolt size for those holes.

 

[nwut05]

I brought a 16x1.5 tap home from work and that is the bolt size for those holes.

Hey that is great information..I went by my local Kubota dealer today and told the part's guy what I was looking for. As usual He get's on the computer and starts searching the diagrams, I told him he would not find them by diagram. After about 3-5 min looking at his computer screen and asking me questions, he turns the screen around so I can see it and says, show me where they are on this diagram. I looked at the diagram, ( of the transmission ) and told him they are on the underside of the shuttle casting in the front of the transmission. He looked at me kinda funny and say's, we don't have any part's listed for that and I don't have a diagram showing the underside of the trans case or even that area. I then explained again that I was already aware of that, and was pretty sure they were 16mm or 5/8 but was hoping he would have maybe an attachment that bolted under there and showed the exact bolt....Here we went again, him typing and scrolling and then he just walked off through a doorway. He came back with 3 bolts. One was a 14mm, one was a 16mm fine thread and one was a 16mm corse thread or standard whichever you call it. He says this is what we think fit's it but we really don't know take e'm, and try e'm. I told him I did appreciate the help but the 14 I knew was too small, and the 16mm course was not the right thread, but I did bring the fine thread 16mm home just in case, and it is NOT the right thread. I said all that to say this, THANK YOU! I will find me a a BOLT NOW! I Hope......

 

[denchen]

There seems to be a lot of guessing on this post. I still would have a go at the basics. As before, I would screw a tight bit of wood into the hole, then measure how many teeth per inch on the marks on the wood. 25.4 mm to the inch would give an idea of the pitch.

 

[LD1]

You say its NOT 16mm fine....why?

Too bit, starts but binds, too small?

At this point you have literally tried everything. You have tried 16mm coarse and fine, you have tried 5/8 coarse and fine, 14mm is too small...

Sorry, but NOTHING is gonna thread in them holes. Because they simply do not make another bolt in those size ranges of what you declare too small and too big. You have damaged and buggered threads and need a tap or chaser to clean them up

 

[KWentling]

Your not going to screw any bolt in those holes with out running a tap in them to clean the paint and crap out first. A 16x1.5 tap screws in with little effort. That IS the size. Not guessing.

 

[nwut05]

Your not going to screw any bolt in those holes with out running a tap in them to clean the paint and crap out first. A 16x1.5 tap screws in with little effort. That IS the size. Not guessing.

ok on the tap understand thank you again

 

[KWentling]

ok on the tap understand thank you again

I'm fortunate to work in a shop that is well equipped and will let me borrow things like taps. Don't be alarmed if your tap brings some metal out with the paint. I noticed on all the holes I have chased with a tap on this tractor the tap cuts a little in the very root of the thread. Good luck with your project.

 

[rScotty]

Ok.
I'm kind of mystified why the 16 mm didn't work.

If I'm understanding right, you've tried 16 mm bolts an/or clean out taps in the common metric thread pitchs :
16 mm coarse = 2.0 mm pitch
16 mm fine = 1.5 mm pitch
16 mm extra fine = 1.0 mm pitch

plus 5/8" in both coarse and fine tpi.

So what does that leave?

 

[LD1]

Ok.
I'm kind of mystified why the 16 mm didn't work.

If I'm understanding right, you've tried 16 mm bolts an/or clean out taps in the common metric thread pitchs :
16 mm coarse = 2.0 mm pitch
16 mm fine = 1.5 mm pitch
16 mm extra fine = 1.0 mm pitch

plus 5/8" in both coarse and fine tpi.

So what does that leave?

Nothing

 

[jonsstihl]

before starting with the tap to clean the holes I would make a chaser with the 16mm 1.5 bolt that was given to you . Cut grooves in the bolt it will be less agressive than a tap.

 

[KWentling]

before starting with the tap to clean the holes I would make a chaser with the 16mm 1.5 bolt that was given to you . Cut grooves in the bolt it will be less agressive than a tap.

Since he has the bolt, it certainly won't hurt to try that. A tap or chaser would be more effective. The reason he is having trouble starting a 16x1.5 bolt is the amount of paint that is in the holes. It may be difficult to get a homemade chaser to start too. Having started a career in machining in 1976 and having access to taps I've never
had the need to make a chaser out of a bolt. I wouldn't try to force it in the hole. Cast iron is prone to galling.

 

[dougtrr2]

Two quick thoughts as it looks like this is about to wrap up.

If they are through holes, maybe try the bolts from the other side.

If they are blind holes, make sure you don't bottom out the tap and snap it off.

Doug in SW IA

 

[rScotty]

Since he has the bolt, it certainly won't hurt to try that. A tap or chaser would be more effective. The reason he is having trouble starting a 16x1.5 bolt is the amount of paint that is in the holes. It may be difficult to get a homemade chaser to start too. Having started a career in machining in 1976 and having access to taps I've never
had the need to make a chaser out of a bolt. I wouldn't try to force it in the hole. Cast iron is prone to galling.

unless it's actually a different pitch of course. I guess it could be a 16x1.0 . Mcmaster-Carr sells that size in super strength alloy for high stress use.


You can make the chaser pretty nicely with a medium hard bolt, a bench vise, a fine cut hacksaw and a firm hand. Keep the slots vertical and straight so the cutting edge of the chaser will be sharp.

I angle the slots back about 15 degrees so that the chaser is partly self-cleaning. If you can make the slots so that they mostly miss the 2 or 3 tapered starting threads on the bolt then the chaser will start nicer.
But like any type of thread chasing, the real trick is to back it out and clean things up every few turns.

 

[nwut05]

I'm fortunate to work in a shop that is well equipped and will let me borrow things like taps. Don't be alarmed if your tap brings some metal out with the paint. I noticed on all the holes I have chased with a tap on this tractor the tap cuts a little in the very root of the thread. Good luck with your project.

Thank You Very much. I got a tap and ran it in the holes and cleaned them out and they work perfectly.

 

[nwut05]

Thank all of you who stayed with this post I have actually seen a lot of tools and gained experience from this and that is what this forums are about. Again thanks to all and it is confirmed for sure 16mm x 1.5 threads in case anyone else ever needs to know. also they are about 40mm deep.

 

[CH4Ohio]

Maybe I missed it along the way. So what was the point of this exercise? Are you planning to bolt something to this assembly? Surely it wasn't just to plug a couple of open holes.

 

[LD1]

Glad you got it all figured out