AISI 4320

AISI 4320

Alloy steels comprise different kinds of steels having compositions exceeding the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon steels. They are designated by AISI four-digit numbers. AISI 4320 alloy steel has high toughness and strength. It contains low carbon content to achieve good welding characteristics.

Chemical Composition


Element Content(%)
Iron, Fe 95.855 - 96.98
Nickel, Ni 1.65 - 2.00
Manganese, Mn 0.450 - 0.650
Chromium, Cr 0.400 - 0.600
Molybdenum, Mo 0.200 - 0.300
Carbon, C 0.170 - 0.220
Silicon, Si 0.150 - 0.300
Sulfur, S  0.0400
Phosphorous, P  0.0350

Mechanical Properties


Properties Metric Imperial
Tensile strength 580 MPa 84100 psi
Yield strength 425 MPa 61600 psi
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson's ratio 0.27-0.30 0.27-0.30
Elongation at break (in 50 mm) 29% 29%
Reduction of area 58% 58%
Hardness, Brinell 163 163
Hardness, Knoop (converted from Brinell hardness) 184 184
Hardness, Rockwell B (converted from Brinell hardness) 84 84
Hardness, Vickers (converted from Brinell hardness) 170 170
Machinability (annealed and cold drawn. Based on 100 machinability for AISI 1212 steel) 60 60

Sheets / Plates

Production Route Hot Rolled, Cold Rolled
Material Standard AISI, ASTM, ASME, DIN, BS, EN, ISO, JIS, GOST, SAE, IS & Custom Chemistry
Size Width from 100mm to 3000mm ; Length from 500mm to 12000mm
Thickness 0.1mm to 400mm
Delivery Condition As Rolled, Annealed, Quenched and Tempered, Normalized
Surface Finish Plain, Brushed, Cladded

AISI 4320 Equivalent Grade / Specifications

  • ASTM A29 (4320)
  • ASTM A322 (4320)
  • ASTM A331 (4320)
  • ASTM A519 (4320)
  • ASTM A535 (4320)
  • ASTM A752 (4320)
  • SAE J1397 (4320)
  • SAE J404 (4320)
  • SAE J412 (4320)

AISI 4320 Applications

  1. Structures in Buildings, bridges, railway stations
  2. Fabrication of pipeline components & Industrial equipment
  3. Construction of automotive bodies, warehouses, shipping containers
  4. Commercial appliances, etc.