Brodie helmet

The Brodie helmet, called Helmet, steel, Mark I helmet in Britain and the M1917 Helmet in the U.S., was a steel combat helmet designed and patented in 1915 by the Briton John Leopold Brodie. Colloquially, it was also called the shrapnel helmet, Tommy helmet, or Tin Hat, and in the United States known as a doughboy helmet.

Brodie helmet in Days of Infamy
The Brodie helmet was standard issue among the US forces stationed in Hawaii and the US Marines. Many Marines hated the new M1 Helmet's they received, preferring the more familiar Brodie helmet, but quickly dropped their criticism after they realised that the old helmet couldn't protect as well as the M1.