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RHA is homogeneous because its structure and composition are uniform throughout its thickness. The opposite of homogeneous steel plate is cemented or face-hardened steel plate, where the face of the steel is composed differently from the substrate. The face of the steel, which starts as an RHA plate,
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MIL-DTL-12560 by several manufacturers. Another standard is MIL-DTL-46177; however, this standard has been inactivated, and all new designs use MIL-DTL-12560. MIL-DTL-46177 RHA is nearly identical to AR500 in terms of tensile and yield strength. The typical
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armour), and the power of anti-tank guns was measured by the thickness of RHA they could penetrate. This standard test has remained in use despite the modern usage of many other types of armour, some of which do not include steel or any other metals.
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or the protective capability of a type of armour which may or may not be steel. Because of variations in armour shape, quality, material, and case-by-case performance, the usefulness of RHAe in comparing different armour is only approximate.
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Today, the term is primarily used as a unit of measurement of the protection offered by armour on a vehicle (often composed of materials that may not actually contain steel, or even contain any metals) in equivalent
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billets of appropriate size and then rolling them into plates of required thickness. Hot rolling homogenizes the grain structure of the steel, changing the crystalline structure of the steel and normalizing it.
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can provide the same amount of protection with much thinner and lighter construction than its protective equivalence in RHA. Likewise, the term is also used as a unit of measurement of penetration capability of
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Armoured steel must be hard, yet resistant to shock, in order to resist high velocity metal projectiles. Steel with these characteristics is produced by processing
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technologies were developed which were capable of relatively easily penetrating rolled homogeneous armour plating even of significant thickness.
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From the invention of tanks through to the Second World War, tank armour increased in thickness to resist the increasing size and power of
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Currently, most armoured vehicles have their basic structures formed from RHA to lend general strength and toughness.
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Since World War II, because of a reduction in effectiveness against new weapons (mainly shaped charges and improved
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link change on May 10, 2009. Contains alloy compositions of military specification armor steels.
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range of MIL-A 12560 is 302-400, making it softer than AR500 which is in the 477-534 range.
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RHA was commonly used during this period (combined with other plate alloys and
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Jamil, W.N.M.; Aripin, M.A.; Sajuri, Zainuddin; Abdullah, Sarwat.
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to improve its material characteristics, as opposed to layered or
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For the testing and calibration of anti-tank guns, the term
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came into use instead of heavy high-velocity projectiles.
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RHA was in common use as primary armour until after
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261:rolled homogeneous armour equivalency
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58:adding citations to reliable sources
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69:"Rolled homogeneous armour"
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450:Bibliography of Tank Armor
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434:Chapel Steel: MIL-A 12560
254:explosive reactive armour
133:Rolled homogeneous armour
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285:United States Army
173:millimetres of RHA
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306:Slat armour
236:Current use
188:Composition
110:August 2022
496:Categories
387:2011-10-10
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322:References
269:projectile
218:cast steel
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159:and other
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300:See also
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