Case-hardened steel armour (Harvey and Krupp)
Blindaje de acero cementado (Harvey y Krupp)
- Date
- c. 1890-1893 · confidence medium
- Place
- United States
- Credited to
- Hayward A. Harvey
- Field
- Conflict
⚠️ Disputed: the sources disagree.
What it is
Steel plates with the outer face hardened by carburisation and the inner face soft, which shattered shells and allowed much thinner armour: 13 inches of Harvey armour equalled 15.5 inches of nickel steel. Adopted by the major navies from the early 1890s, it was superseded by Krupp armour later in the decade.
The Harvey process was developed in the early 1890s and spread through a syndicate of manufacturers (Vickers, Armstrong, Krupp, Carnegie, Bethlehem Steel, 1894); the exact place of the invention is not documented here and the date is approximate.
What it led to
- late 19th-century battleships and dreadnoughts
- lighter ship armour
- the gun-versus-armour race up to Krupp armour