Eli5, why do Mason jar lids typically come in 2 parts, threads and seal, as opposed to nearly every other commonly used household container?

Question

Eli5, why do Mason jar lids typically come in 2 parts, threads and seal, as opposed to nearly every other commonly used household container?

In: 7899

Answer 1

Their designed for canning.

When you can something you boil the jar under water. The liquid inside starts to evaporate and exits through the seal. You then pull it out of the water and it cools and condenses. This creates that pressure differential that causes the top to pop when you open it.