Fit grade for plastic container

Myint Mo,

ANSI and ISO tolerance tables are a guide for press-fit metal parts. If you are trying to seal two plastic parts using inteference fits, you will have to do some engineering, and some practical testing, I am sure.

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JHG

Frankly, I would not trust an interference fit to remain airtight on a pair of plastic parts. Creep of plastics is part of the game, and over time any interference fit will not remain so.

If you want this to be a temporary fit, use a set of conical fits, like in a luer fitting on a hypo syringe and needle.

If you want this to be a permanent airtight assembly, look at various methods (ultrasonic, hot plate, laser...) of plastic welding or glue bonding.

Edit: another alternative would be to design in an elastomeric seal element (e.g. an o-ring or similar gasket seal).