Mystery solved: why do the padlocks have a small hole?

Chains are not the only objects with little-known but ingenious detail. For example:

• Some screwdrivers have a slot on their handle allowing them to be used with a key for better leverage.
• The small pocket on the jeans was originally designed to store a pocket watch.
• The holes in the spaghetti spoons are used to dose the ideal amount of pasta for a person.

These little design attentions show how everyday objects are designed to be practical and functional.

A simple but ingenious design

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