The word tough can be defined as able to withstand strain, solid, rugged and formidable among other terms. Certain drivers in NASCAR's premier series epitomize toughness for a variety of reasons.
Drivers can be tough without having a persona that would be described in such a manner. They may just be tough competitors who are formidable contenders for race wins and championships.
Other drivers can have the intimidating factor with their aggressive driving style. When these drivers are running well, they can give a competitor a few extra heart palpitations when they close fast on a car.
Those who succeed as Cup drivers must be able to withstand the pressure of racing at such a high level, so every driver is tough to some degree, in addition to having the ability to wheel the race car.
In this slideshow, drivers who might be considered the toughest in the series will be highlighted.