Twist-off type threads design and manufacturing

[Fibre and resin guy]

Hello all,
I am looking for some references (handbooks, tutorials, etc) related to the design of twist-off type threads, similar to those that can be found on jar lids for instance.
I suspect these are partial threads with a very high pitch, but would be happy to have some advice or rulle of thumb on features such as angle, depth, interruption, etc.

Also any info on machining (if metal) or moulding (if plastic) these would be very welcome.

All the best.

 

[3DDave]

Jar lid thread dimensions - Google says:

https://www.paramountglobal.com/knowledge/jar-neck-thread-finish/

They refer to the Glass Packaging Institute (GPI) and the Society of Plastics Industry (SPI)

 

[Fibre and resin guy]

Thanks, that's a starting point !
Apparently there is a german standard too, but most of the info I find relates to the overall dimensions rather than the thread profile/pitch.

 

[LittleInch]

Well you probably want the whole thing to take place in 45 degrees or movement from off to fully sealed.
They gives you an idea of pitch thread once you know how far you need to move the lid / device down into / onto the other part.

But then you also get sprung bayonet type things like light bulbs or pressure washer fittings.

Your force if its a human hand is about 50N at the outer edge or maybe less if its smaller or you need to grip it tight.

I'm amazed there is a glass packaging institute, but my guess is that a lot of this is simply trial and error / testing / long standing designs

You probably need at least three or more connections to have a smooth pull or force.

Any more details on what this is?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Fibre and resin guy]

Hello,
I'd like to find a clever way to clamp a two parts insert for a composite plate with a hole during bonding, with minimal rotation to keep the two parts roughly aligned (for cosmetic reasons) even if plate thickness varies slightly.

 

[IRstuff]

A picture would be useful

TTFN (ta ta for now)
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[3DDave]

Thread profile and pitch should be available from the organizations mentioned. They are going to be mostly interested in mass manufacturers of jars and lids.

If you want something else, buy some and measure them. Pitch and profile are easy.