SITHERM S353R is a premium hot work tool steel grade with improved toughness, better resistance to heat cracking, wear and plastic deformation. It is used in hot-work applications like die casting, die forging and extrusion.


Why choose SITHERM S353R?

Improved toughness (≥ 23 J) 

SITHERM S353R is characterised by elevated toughness and is specifically designed for demanding hot-work applications where resilience and durability are required.

KV impact specimens (EN ISO148-1:2017 / ASTM A370-05-17) are used to test impact toughness in a short transverse direction.

Specimens are quenched and tempered to 45+/-1 HRC, and test is performed at 20 ̊ C. Average impact toughness of forged
quality is higher than 23 Joule for the average forging size of blocks up a thickness of 500 mm. (NADCA#229-2016).

Improved Thermal Fatigue Resistance

SITHERM S353R demonstrates resistance to thermal fatigue within the standard hardness range for hot-work applications. This attribute holds significant value in processes where maintaining structural integrity under thermal stress is paramount.

Extended component lifespan

SITHERM S353R durability ensures reliable tool performance over an extended period, enhancing process efficiency and contributing to the overall success of your project.

Other properties

  • Excellent cleanliness
  • High temper resistance and high-temperature strength
  • Excellent hardenability
  • Suitable for nitriding 

Extensive application posibilities

SITHERM S353R is primarily designed for die casting of light metals and alloys as well as extrusion and die forging. It is often used for highly stressed hot-work structural parts where superior toughness is required. Suitable for large structural casts/parts.

It is recommended for die forging and extrusion. 


In December 2023, we received confirmation that SITHERM S353R had successfully passed the rigorous testing procedures of the North American Foundry Association (NADCA).



AISI W. Nr. C Si Mn Cr Mo V
1.2367 mod ~1.2367 0.36   0.30   0.30   5.00   2.30   0.60  


Available from stock


up to 762 x 407 mm

Delivery condition

SITHERM S353R is supplied in annealed condition, max. 229 HBW.



How does SITHERM S353R compare to commonly used H13/1.2344 hot work tool steel when exposed to demanding operating conditions? 
Check out our latest case study which evaluates their performance in the high-pressure die-casting shotblock application.


Product Data Sheet

You can find more detailed information in the downloadable datasheet.

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