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Alloy Steel Billet

4340 alloy steel (also known as AISI 4340) is a low alloy steel with high toughness in an annealed state. 4340 alloy steel is characterized by its outstanding ductility, formability, and weldability rendering it an excellent metal for a variety of structural applications and components including power transmission gears and shafts, aircraft parts, and machinery. 4340 steel is mainly iron based, with nickel being the other major chemical property. Standard specifications for 4340 include AISI 4340, AMS 6359, ASTM A711 and more.

At Rickard Specialty Metals, we have 25+ years of supplying 4340 steel forgings, sheet, plate and more to your custom measurements. Our forging process includes open die forgings, ring rolling and more. Additionally, we provide 4340 heat treatment. See below for a list of common 4340 forged shapes, including 4340 steel flat bar and round bar, as well as the additional product forms we offer.

NOMINAL COMPOSITION

  • C     .38 – .43
  • Cr    .7 – .9
  • Mn    .6 – .8
  • Mo    .2 – .3
  • Ni    1.65 – 2
  • P     .035 max
  • Si    .15 – .3
  • S     .04 max
  • Fe    Balance

STANDARD SPECIFICATIONS

  • AISI 4340
  • AMS 6359
  • AMS 6409
  • AMS 6414
  • AMS 6415
  • AMS 6454
  • ASTM A29 (4340)
  • ASTM A320 (L43)
  • ASTM A322 (4340)
  • ASTM A331 (4340)
  • ASTM A506 (4340)
  • ASTM A519 (4340)
  • ASTM A646 (4340-7)
  • ASTM A711
  • ASTM A752 (4340)
  • ASTM A829
  • MIL S-5000
  • SAE J1397 (4340)
  • SAE J404 (4340)
  • SAE J412 (4340)
  • UNS G43400

4340 FORGINGS

  • 4340 Steel Round Bar
  • 4340 Steel Flat Bar
  • 4340 Steel Rectangular Bar
  • 4340 Steel Rolled Rings
  • 4340 Steel Forged Rings

OTHER PRODUCT FORMS

  • 4340 Steel Disc
  • 4340 Steel Sheet
  • 4340 Steel Plate
  • 4340 Steel Extrusion
  • 4340 Steel Extrusion angles
  • 4340 Steel Billet
  • 4340 Steel Ingot
  • 4340 Steel Machined Parts
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