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FLEXOR® Superior Steel Alternative to

4340 Alloy Steel

Pennsylvania Steel Corporation offers an alternative to SAE 4340 alloy steel.

We produce FLEXOR® steel to be similar if not superior in its mechanical properties to 4340 alloy steel. Taking this into account, it is suitable and can be utilized in most of the same applications as 4340 alloy steel.

Being a proprietary grade, Pennsylvania Steel ensures that all FLEXOR® heats meet the high quality vacuum degas electric arc furnace melt process in order to ensure cleanliness, grain refinement and maximum reductions.

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4340 aisi & sae alloy steel

4340 Steel Applications

  • Automotive
  • Oil and Gas Drilling
  • Forging
  • Warm and Cold Forming
  • Performance Racing
  • Powdered Metal
  • Die Casting
  • Machine Building
  • Tool Making
  • Work-holding
  • Transfer Systems

Typical FLEXOR® Mechanical Properties (Based upon 1.00” dia.)

Mechanical Properties 30 HRC 40 HRC 45 HRC
UTS(ksi) Per ASTM E8-04 147 183 225
YS 0.2% offset Per ASTM E8-04 134 171 205
V-Notch Charpy Impact Per ASTM E23-06 80 45 21
RA% Per ASTM E8-04 64 60 50
Elongation Per ASTME E8-04 21 18 12
Poisson's Ratio per ASTM E111-04   .282  
Young's Modulus per ASTM E111   30900 (ksi)  

4340 Steel Chemistry Composition

Alloy 4340 FLEXOR®
Carbon, C .37-.43 .32-.36

Manganese, Mn

.60-.80 .60-.80

Phosphorous, P

.035(max) .025(max)

Sulfur, S

.04(max) .025(max)

Silicon, Si

.15-.35 .15-.30

Chromium, Cr

.70-.90 .75-1.00

Molybdenum, Mo

.20-.30 .40-.60

Nickel, Ni

.1.65-2.00 .25(max)

Tungsten, W

- .40-.70

Often the limitations and inconsistencies of common 4340 alloy steel can be frustrating and may jeopardize the success of your project or application.

Contact Pennsylvania Steel Corporation today to learn more about FLEXOR® and its advantages over 4340 alloy steel.

FLEXOR® Properties

FLEXOR®'s dependable quality and adaptability in heat treatment allows for a wide range of physical properties that are more appealing than those of typical ASTM, AISI or SAE 4340 alloy steel.

FLEXOR® has a comparable core hardness which typically means a more uniform hardness through any cross section. The more uniform the hardness along with a fine grain microstructure yields a higher fatigue and tensile strength for difficult  applications. FLEXOR® has an added benefit over 4340 alloy steel. Unlike the Nickel based 4340 FLEXOR® does not have to worry about the work hardening that often takes place during machining with Nickel based steels. Please compare total percentage of Alloy above.

FLEXOR® Sizes & Conditions

FLEXOR® steel is available in a variety of sizes and conditions. These include, but are not limited to:

  • Decarb free alloys
  • Hot rolled flats
  • Hot rolled rounds
  • Hot rolled plates
  • Peeled steel bars
  • Turned forged rounds and billet
  • Ground and polished rounds

Questions? Ask Our FLEXOR® Experts

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