This Is Why Some Window Grills Have a Curve at the Bottom – It’s Not Just for Looks

It’s not just aesthetic.
It’s smart engineering — a centuries-old solution to a very real problem.
Let’s explore why some window grills have a curve at the bottom — and why this small detail makes them stronger, safer, and smarter.
🔧 The Real Reason: Structural Strength Through Shape
The curved bottom on a window grill isn’t random.
It’s a reinforcement technique — based on the same principle that makes arches so strong in bridges and doorways.
When metal bars are curved:
When metal bars are curved:

They distribute weight and pressure more evenly

They resist bending and warping

They withstand force from multiple directions

A straight horizontal bar can sag over time — especially if it’s long or made of thinner metal.

But a curved bar?

It acts like a spring, absorbing stress and bouncing back.