385 (MIL-A-12560)

MIL-A-12560 Grade 385 is a rolled homogeneous armor (RHA) steel plate engineered to provide an exceptional balance of hardness, toughness, and ballistic protection for military and defense applications. With a nominal hardness of approximately 385 Brinell (BHN), this grade offers improved resistance to penetration over the standard 360 BHN armor plate, while maintaining enough ductility to absorb impact energy without cracking.

385 meets and exceeds the requirements specified in MIL-A-12560 (appendix A Class 1).

Property

specification

Weldability

Carbon equivalent of 0.72 Typical

Mechanical Properties (ASTM A370)

Hardness
Yield Strength (Typical)
Tensile Strength (Typical)
Elongation 2″ (Typical)

363-400 BHN
172 Ksi
191 Ksi
10% (in 2″) (ATSM E10)

1187 MPa
1318 MPa
10% (in 50mm)

Charpy V-Notch Impact (ASTM A673) BEND TEST

Standard size, 17 foot-pounds (23 joules) @ -40 deg C/F test temp, transverse direction hardness 363 BHN. (note the complete requirements are in MIL-A-12560J Table V) 4T (up to .50 inches-12.5mm)

Flatness

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

Thickness

The requirements are 50% of that specified in ASTM A-6. Special tolerances are available (subject to SWC approval).

Ballistic Testing

The requirements of 385 meet and exceed the requirements specified in MIL-A-12560 J (appendix A Class 1). 385 has been qualified at Aberdeen (US Army Proving Ground). Production lot qualification is performed at an approved test facility.