Chronically angry employees are often toxic to a work environment, and sometimes a genuine threat. They poison the atmosphere and sabotage the camaraderie a team needs to function, often because the team focuses so much on not setting off these easily enraged employees.
Research by the Centers for Disease Control, the Bureau of Labor Statistics, and the U.S. Department of Justice estimates that 50 percent of American workers have reported "desk rage" - e.g., verbal abuse and yelling - from co-workers at their jobs. This might sound like the stuff of "Dilbert" cartoons or the movie "Office Space," but when such anger goes unchecked, it eventually leads to physical violence in approximately one out of every 10 workplaces.
You are responsible for establishing an environment where your staff members feel secure and can be productive. To maintain that safe harbor, meet with the employee in question, and let him know that while you understand he may be frustrated, his method of showing it is simply unacceptable. Tell him his actions are perceived as threatening to the safety of others who work with and around him, and that if any such outburst occurs again, he will be suspended for a period to give him time to seek help with anger management. Any further such displays would be considered terms for dismissal.