Is it possible to machine a Mason jar thread on a lathe?

[KJP]

Is it possible to machine a Mason jar thread on a lathe? More specific would be a humming bird feeder bottle thread. I have a five gallon bucket half full of these humming bird feeders with cracked or split part of the feeder that screws to the top part of the bottle. I have been careful not to over tighten them but still they crack from sun exposure I suspect. It’s not the cost of a new $15 feeder, but if there is a simple fix, I sure would like to try it. Anyone having a homemade feeder design and willing to share would be appreciated.

 

[Jon_Spear]

The nice thing about lathes and milling machines is that you can make so many mechanical things on them.

Some jar threads are multiple start. There are various ways of doing multiple threads, depending on your lathe and the setup.

I am looking at my spaghetti sauce jar, and it is a single thread, about 4tpi. The profile is neither acme nor a 60-degree point. It looks sort of like a continuous "S" shape. I guess you'll have to grind your own threading toolbit for this one. Sounds fun, an excuse to put your lathe to use.

 

[winchman]

You might do better making something that would fit in place of the sealing cap that goes on the mason jar, and use the standard mason ring to hold it in place.

An alternative would be to make something that holds the mason ring itself, but that wouldn't seal very well.

Either way you wouldn't have to mess with making the wierd thread.

Roger

 

[TheMetalDoctor]

Why don't we all boycott hummingbird feeders until they come out with a thread that can be easily cut on our lathes?

TMD

 

[KJP]

Jon
You are right about the four threads per inch and thank god it is not multiple start threads. The bottom of the thread OD of the bottle is 2.360” and the OD to the top of the thread is 2.460”. The thread is weird with a taper on one side and flat on the other side.

 

[CharlieBiler]

KJP,
Standard jar threads are 5, 6, 8, and 12 threads per inch. The different threads are not geometrically similar. You probably are looking at the standard narrow mouth canning jar. It is 5tpi.
The height of the 5 tpi thread is 0.060". The radius of the thread top is 0.044". The radius of the base corner roots is 0.030" max. The sides of the threads are thirty degrees from vertical.
I suggest you follow winchman's suggestion. They are a bear to turn.
By the way, Mom worked in a glass house (factory) for 35 years. Dad was in a glass house for 46 years. I worked there until the entire industry was legislated to death, and sold out. It is called a house because it is your home. I would walk barefoot over hot coals to go back to that hell of a glass house. The work was insane, but it beats making televisions. The people that worked there were also much better. Political corectness was not tolerated in our little hell on earth. After a while you have no fear of hell. You work there, get a decent paycheck, and you know just what the boss is. Everything else just falls in to place.

 

[jlaiii]

KJP,
Standard jar threads are 5, 6, 8, and 12 threads per inch. The different threads are not geometrically similar. You probably are looking at the standard narrow mouth canning jar. It is 5tpi.
The height of the 5 tpi thread is 0.060". The radius of the thread top is 0.044". The radius of the base corner roots is 0.030" max. The sides of the threads are thirty degrees from vertical.
I suggest you follow winchman's suggestion. They are a bear to turn.
By the way, Mom worked in a glass house (factory) for 35 years. Dad was in a glass house for 46 years. I worked there until the entire industry was legislated to death, and sold out. It is called a house because it is your home. I would walk barefoot over hot coals to go back to that hell of a glass house. The work was insane, but it beats making televisions. The people that worked there were also much better. Political corectness was not tolerated in our little hell on earth. After a while you have no fear of hell. You work there, get a decent paycheck, and you know just what the boss is. Everything else just falls in to place.

I am also interested in machining a top for a Ball Wide Mouth jar. Any idea what the thread shape and pitch is? I would use a 3-axis cnc mill in my attempt.

 

[Davis In SC]

Why don't we all boycott hummingbird feeders until they come out with a thread that can be easily cut on our lathes?

TMD

Naa, that is almost as bad as putting Sweet & Low in them...

 

[grbl]

Check the date on the post you're replying to

 

[Hardened]

Check the date on the post you're replying to

But with important issues such as this, is time really relevant?