360 (MIL-A-12560)

MIL-A-12560 is a U.S. military specification covering rolled homogenous armor (RHA) steel plates used in the fabrication of armored combat vehicles and protective structures. This specification ensures superior ballistic resistance, strength, and toughness across multiple hardness levels. Commonly referred to by its nominal hardness, 360 Brinell, this grade delivers a balance between impact absorption and resistance to penetration, making it ideal for military and defense applications where reliability and protection are critical.

360 Steel Plate Specifications

Weldability

Carbon equivalent of 0.64 Typical

Mechanical Properties (ASTM A370)

Hardness Yield Strength (Typical) Tensile Strength (Typical) Elongation 2″ (Typical) 341-388 BHN 158 Ksi 175 Ksi 12% Rc 35-39 (for reference) 1090 MPa 1205 MPa

Charpy V-Notch Impact (ASTM A673)

Standard size, -40F test temp: at a hardness of 363 BHN – 17 ft-lb. (note the complete requirements are in MIL-A-12560H Table V)

Flatness

Requirements are 50% of that specified in ASTM A-6. Tighter flatness tolerances are available (subject to SWC approval).

Thickness

The requirements are specified in MIL-A-12560H Table 3. Special tolerances are available (subject to SWC approval).

Ballistic Testing

360 meets and exceeds the values specified in MIL-A-12560H, Class 1. All Ballistic testing has been performed at Aberdeen or a US Military approved facility