4140 Annealed

*Always consult your Heat Treater*
     *Information Provided is General*


4140ANN is a widely used quenched and tempered medium carbon alloy steel. 4140ANN is oil-hardening steel of relatively high hardenability. The chromium content provides good hardness penetration, and the molybdenum imparts uniformity of hardness and high strength. The grade is especially suitable for forging because they have self-scaling characteristics, respond readily to heat treatment and are comparatively easy to machine in the heat-treated condition. 4140ANN maintains their properties even after long exposure at relatively high working temperatures. With a combination of such highly desirable properties as good strength and wear resistance, excellent toughness coupled good ductility, and the ability to resist street at elevated temperatures, it is understandable why these are widely used and highly successful alloy steels.

4140ANN is excellent for tooling and maintenance applications and numerous machine component parts. The countless applications include backup and support tooling, die details, short run dies, arbors, spindles, brake dies, axles, bolts, forming rolls and other machine tool components. This heat-treated medium carbon alloy has every requisite for all around good service in applications requiring wear resistance toughness, high mechanical properties and good machinability.

4140ANN has 0.02 less carbon than 4140/42PH.

The 4140ANN that Windsor Steel Corporation has in stock is an annealed materials versus the 4140/42PH which is a pre-heat treated material.

Hardening happens between 1525 – 1625°F.


  •  + .020 up to .035 on thickness

  •  + 1/16″ up to 1/8″ on width


  •  1/4″ dia. up to 3″ dia. + .000 – .004

  •  3 1/4″ dia. up to 11″ dia. +/- 1/16″

 Hardening Temp.:    1525°F thru 1625°F

 Quench Medium:    Oil

 Tempering Range:    400°F thru 1300°F

 Forging Temp:    2100°F thru 2200°F

 Anneal Temp.:    1450°F thru 1550°F

 Anneal Hardness:   187 BHN

 4140ANN Material In Stock

 Color Code:    BLUE & YELLOW

 Flat Dimensions

  • 1/4″ x 1″ up to 6″ x 6″

  • Non-standard sizes, quoted upon request

 Round Dimensions

  • ¼” up to 12″

  • Non-standard sizes quoted upon request.

 4140 Annealed Typical Analysis











 · Slight variations from typical analysis shown may occur in order to  maintain the desired graphitizing potential.