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Download ExELL™ 420-SMDQ Spec sheet

ExELL™ 420-SMDQ is a premium grade stainless steel used in many tooling applications with these typical properties:

  • Good corrosion resistance
  • Very good polishability
  • Excellent steel cleanliness
  • High working hardness/strength
  • Good wear resistance
  • Very good stability in hardening


ExELL™420-SMDQ is used in various applications and is especially recommended for most types of molding tools where the unique properties of ExELL™ 420-SMDQ are required.

Corrosion resistance. For extruding or molding corrosive materials such as PVC and acetates and for molds or engineering parts subjected to mild corrosives or to humid working or storage conditions.

Very good surface finish: When polishability requires an excellent surface for release, minimal stress raisers, the molding production of most optical parts of the molding of medical and the food industry parts such as containers.

Good wear resistance. Very suitable for certain adhesive or abrasive wear resistance requirements. For molding abrasive filled plastics and for long or high production runs.


C 0.38 Mn 0.45
Si 0.75 Cr 13.75
V 0.30



USE Typical Hardness HRC
Engineering Part 50–54
Injection Molds 50–54
Extrusion or Pultrusion Dies 46–54
Compression or Transfer Molds 50–54
Blow molds for PET or PVC 46–54


Note:Most applications of ExELL™ 420-SMDQ utilize the optimum combination of corrosion resistance, hardness and toughness properties attained by heat treatment with hardening at 1870F and double tempering at 480F.


 Physical Properties:

Coefficient of Thermal Expansion, in/in/F

70 – 400 F 0.0000060
70 – 600 F 0.0000064


Thermal Conductivity, BTU in/ft2 hr F

70 F 160
400 F 168
750 F 175


Density, lbs/

70 F 0.2833
400 F 0.280
750 F 0.276


Modulus of Elasticity, psi

70 F 29,200,000
400 F 28,000,000
750 F 26,500,000


Specific Heat, Btu/ibF

70 F 0.115


Critical Temperatures
Ac1 – 1470F

Ac3 – 1580F

Ms – 325F


HEATTREATMENT(General Recommendations)


After rough machining of an annealed component, heat the part to 1200F, equalize and hold 1 – 2 hours. Furnace cool to 900F and then air cool to room temperature.


With a protective atmosphere or vacuum furnace, heat slowly to 1450F. Equalize and hold one hour per inch of thickness. Furnace cool 20F/hr to 1200F and equalize. Air cool to room temperature. Hardness – 229 HB max.


Protect against decarburization and oxidation during austenitizing.

Preheating: Heat to 1200F and equalize. Continue heating to 1550F and equalize. Complete heating to hardening temperature.

Hardening: Typical austenitizing range is 1870 – 1920F. Hardening temperature can be adjusted to develop maximum hardness. A hardening temperature of 1870 – 1880F is normally used for most applications while 1910 – 1920F can be used for maximum hardness.

Hardening Temperature Hold Time* As-Quenched Hardness
1870F 30 min.* 56±2 HRC
1910F 30 min 57±2 HRC

*Hold time = time at temperature after tool is fully heated through.

Quenching: Quenching should be performed as rapidly as possible without promoting excessive movement or cracking. Typical quenching media include:

  • High speed gas with sufficient positive pressure in vacuum furnace
  • Circulating air/atmosphere
  • Martempering bath or fluidized bed at 480–1020F, then air cool to room temp.
  • Warm oil


Temper immediately after quenching to about 150F. Temper a minimum of two times with intermediate cooling to room temperature.

Choose the tempering temperature to develop required hardness. (However, tempering at 480F is recommended for the optimum balance of hardness, toughness, corrosion resistance and dimensional stability.) ExELL™ 420-SMDQ should be heated to the desired tempering temperature and held a minimum of two hours. Air cool to room temperature. Check hardness and adjust temperature for additional tempering operation(s). Repeat for added tempers.

Typical tempering temperature responses follow (use for approximate guideline only):

Tempering Temperature Harden 1780F HRC Harden 1910F HRC
480F 52 53
570F 52 53
750F 51 52
930F 52 54
1020F 46 47
1110F 40 40

*Avoid tempering between 750–1020F due to risk of temper embrittlement and loss of corrosion resistance.


Typical tensile & yield strength at RT

52 HRC 46 HRC
Tensile Strength, psi 255,000 210,000
0.2% Yield Strength, psi 215,000 185,000


ExELL™ 420-SMDQ resists rusting and staining due to humid service or storage conditions. Additionally, ExELL™ 420-SMDQ will resist typical corrosion by water, water vapor, weak organic acids and when molding corrosive plastics under normal conditions.

ExELL™ 420 SMDQ will exhibit maximum corrosion resistance when using a low temperature temper (480F) in heat treatment and when polished to a very fine finish.


ExELL™ 420-SMDQ is manufactured to the highest premium quality requirements to provide molders with long life tools with low maintenance costs for the best molding economy. This controlled high quality also offers toolmaking very consistent steel properties. For additional information including specifics on machining, welding, grinding, polishing or EDM processing, please contact Ellwood Specialty Steel direct at 800-932-2188.


Ellwood Specialty Steel is a fully integrated producer of a wide range of specialty tool steels. Our ExELL™ grades are made with advanced ASEA-SKF steel making capabilities which include an ultra high powered electric arc furnace with subsequent state of the art ladle refining and vacuum degassing equipment for the most complete and modern ladle metallurgy technology.

Our steel making expertise and capability is further enhanced from a long forging history with optimum forging and heat treating practices to develop very special material characteristics of product uniformity, cleanliness, machinability polishability, strength, toughness, hardenability  and other steel properties. All this from production facilities certified to ISO 9002.


Ellwood Specialty Steel is committed to providing products and services which will consistently meet or exceed all quality and performance expectations. We will provide customer and technical service that will ensure complete satisfaction.

Being a very flexible integrated producer, Ellwood Specialty Steel will establish product programs to fully support industry or customer requirements. Our extensive stock programs are supported by very short mill lead times of custom forged products. Customized stock programs are and can be available for specific customer needs.

This information is intended to provide general data on our products and their uses and is based on our knowledge at the time of publication. No information should be construed as a guarantee of specific properties of the products described or suitability for a particular application. Ellwood Specialty Steel reserves the right to make changes in practices which may render some information outdated or obsolete. Ellwood Specialty Steel should be consulted for current information and/or capabilities.


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