Steel Cap

Some Elven Warriors, as the Fighters of the House of the Mole in Gondolin, were described to wear round Steel-cap Helmets.

speculations
The Elven steelca-type Helmet is not described in detail, but it may have been akin either to the orc-helm, possibly a kind of Ironhat, or maybe the númenórean Karma-Helmet, which may have been inspired by the historical burgonet.

movie trilogy
In the Movie Trilogy Haldir´s Galadhrim Warriors wear helmets resembling round skull-caps.