4140 alloy steel
4320 Alloy Steel Bar Alternative

Superior Steel Alternative to

4140 Alloy Steel

Pennsylvania Steel Corporation presents an alternative to SAE 4140 alloy steel.

FLEXOR®'s chemistry and mechanical properties are comparable, if not superior to 4140 alloy steel and thusly, can be utilized in most of the same applications. Being a proprietary grade Pennsylvania Steel insures that all FLEXOR heats meet the high quality vacuum degas electric arc furnace melt process in order to insure cleanliness, grain refinement and maximum reductions.

FLEXOR® 4140 Alloy 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

FLEXOR®'s consistent quality and versatility in heat treatment allows for a wide range of physical properties that are more appealing than those of typical ASTM, AISI or SAE 4140 alloy steel. Higher core hardness 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. Please compare total percentage of Alloy below.

FLEXOR® steel is available in a variety of sizes and conditions. These include, but are not limited to, decarb free alloys, hot rolled rounds, peeled steel bars, ground and polished rounds, hot rolled bars, hot rolled plates, turned forged rounds and billet.

4140 Alloy Steel Chemistry Composition:

  C Mn P S Si Cr Mo W
4140 Steel .38-.43 .75-1.00 .035(max) .04(max) .15-.30 .80-1.10 .15-.25 -
FLEXOR .32-.36 .60-.80 .025(max) .025(max) .15-.30 .75-1.00 .40-.60 .40-.70


4140 (x1000 kg/m3) 7.7 - 8.03 @25°C
FLEXOR® 7.543g/cm3 per ASTM B311

Specific Heat

4140 (J/kg-K) 473 @150 - 200°C
FLEXOR® .16 Btu/lb/°F

The limitations and inferiority of 4140 alloy steel can be frustrating and jeopardize the success of your project or application.

Contact Pennsylvania Steel Corporation today to learn more about FLEXOR® and its advantages over 4140 steel.

TYPICAL FLEXOR® MECHANICALS (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)

Contact one of our sales representatives today
to inquire about a quote from Pennsylvania Steel
or call us today at 1-866-935-3967

Request Information

Have A Questions?

* Indicates a required field