Cosworth understands how important the roll of a head stud is in your high performance motor. That's why they put so much effort into manufacturing these to their idea of perfection.
Exposing these studs to heat treatment and rolling each stud individually creates a unique, perfectly straight, finish that ensures strength and consistency in every stud.
Cosworth prides themselves on ensuring every stud they put their name on by running strenuous testing and performance standards before they're sold to the public. Push your power to the limit and know that these will be able to hold up under extreme pressure, heat, and constant, high-intensity wear and tear.