How much stronger is Carbon Fiber than Steel?

Introduction

How much stronger is Carbon Fiber than Steel? That is the question that we will try to answer today.

A few years back BBC did a documentary comparison on race car drive shafts. They compared a steel driveshaft vs a carbon fiber drive shaft, most of you know the result but I still want you to see this video ☺

Watch this Video

Dissecting the Numbers

Did you see how the steel drive shaft started bending and eventually corkscrewed? Yes you did.

Did you see how the carbon drive shaft started bending and eventualy corkscrewed. NO YOU DIDN’T!

The carbon fiber drive shaft took all that pressure like a champ. It didn’t even budge!

So how much stronger is carbon fiber than steel?

According to the specs in the test done by BBC Engineering the Steel Drive Shaft only “lasted” up to 1376 newton meters, while the carbon fiber drive shaft reach all 4728 newton meters. If we divide those two number we can 3.436….. which means it took 3.43 times more force to break carbon fiber took than it did to break the steel shaft.

You might be thinking 3.43x?! That’s it? Well not quite.

What we have to take into consideration is that we didn’t factor in the weight of the materials.

If estimating I’d say the carbon fiber drive shaft is at least 5x lighter than the steel shaft, and this is being very humble (it might be closer to 10x lighter). But lets go with 5x to be fair.

Now lets do so simple math. To fairly calculate and compare the 2 materials, we’d have to multiple the weight factor number by the previous strength factor number that we came up with before. So we said earlier that based on the test carbon fiber was 3.43x stronger. We also figured that the carbon drive shaft is approximately 5x lighter than the steel shaft. So all we do is plug the two numbers into a simple formula and solve: