Go to Navigation Go to Content

4340 CD Steel Bar

Cold rolled 4340 steel bar is widely used throughout the aerospace industry because of its high strength and ductility properties. This grade is a medium carbon nickel-chromium-molybdenum that has good shock and impact resistance. 4340 CD bar is utilized by a variety of high stressed applications and parts because this grade has excellent toughness and preserves good fatigue strength when heat treated. Eaton Steel Bar Company stocks several diameters of this grade to meet your demands quickly. We also supply 8620 cold drawn steel bar to various industries like aerospace, construction, automotive, and more.

4340 cold-rolled-steel-bar

4340 Cold Drawn Steel Bar Applications

Typical applications for this grade include aircraft landing gears, aerospace landing parts, drilling parts, and shafts.

Shapes and Sizes

Eaton Steel Bar Company supplies 4340 cold drawn steel bar in a variety of sizes ranging from – 1 ½”-11”. The shapes available for this grade include:

  • Rounds

Standard "4340 Grade" Chemical Composition

Carbon 0.38-0.43
Manganese 0.60-0.80
Phosphorus (max) 0.035
Sulfur (max) 0.040
Silicon 0.15-0.35
Nickel 1.65-2.00
Chromium 0.70-0.90
Molybdenum 0.20-0.30


Estimated Mechanical Property Ranges for "Grade 4340 Annealed"

Tensile strength (psi) 100,000 - 110,000
Yield strength (psi) 90,000 - 100,000
Elongation in 2” (%) 15 - 25
Reduction of area (%) 50 - 60
Brinell Hardness (BHN) 210 - 240