The Brodie helmet is a steel combat helmet designed and patented in London in 1915 by John Leopold Brodie. A modified form of it became the Helmet, Steel, Mark I in Britain and the M1917 Helmet in the US.

Here a manufacturer's marked example of such helmet. Marked with "ZF 45" on the reverse rim. Missing parts of the Interior. Base strap showing the 7 1/2 size. Helm has been compromised and shows a major dent and hohle. Possible seen combat.