Most People Don't Know the Function of This Construction Equipment. Do You?
This is one of the most widely used construction tools—but what makes it so popular?
Correct Incorrect Before the invention of the hard hat, laborers used tar and leather to protect their heads. The "hard-boiled hat," made from glue, steamed canvas, and black paint, was patented in 1919. Starting in 1931, some projects, like the Hoover Dam, required workers to wear hard hats for safety.