Background

Aluminum is a popular material, especially in construction. It is very easy to bend, form, and cut, which makes it a great material to work with. Many metals need to be hardened or softened, depending on what type of project they are used for.

The way a metal is processed affects its strength. The nails in this package are an excellent example. Both came from the same package when purchased. They are made from aluminum alloy 6061 and have a deformation strength of about 40,000 psi. For demonstration purposes, half of these nails were subjected to a heat treatment designed to weaken the metal. The resulting strength is only 8,000 psi — one-fifth of the non-treated nails!

This experiment demonstrates how heat affects aluminum nails!

The Experiment

To observe some differences between the two nails, drop each one from waist height onto a concrete floor and listen to the sound. The weak nail impacts with a “thunk,” while the hardened one emits a sharp “ping” and bounces upon impact.

Then do one of the following:

(1) Try to bend the nails with your bare hands — one is easy and one is difficult.

(2) Try driving each nail into a block of wood. The difference should be obvious.

So why use aluminum?

For one, it's highly recyclable.

It’s actually one of the most sustainable metals out there.

Additionally, it’s lightweight and strong. Pound for pound, it’s actually stronger than steel. It’s around 1/3rd the weight of steel, but it can carry 2/3rds of the same load that structural steel carries.