Sleipner Steel

4 min


Sleipner Steel

Sleipner or Uddeholm Sleipner steel is a high-alloy cutlery steel with a wide range of properties and is an ideal steel for all types of surface treatments.

This combination makes Uddeholm Sleipner extremely versatile and suitable for medium production cycles in cold applications.

Data Sheet – Uddeholm Sleipner

In East Asia and Southeast Asia, Uddeholm Sleipner is marketed by Assab under the brand name Assab 88.

  • Good wear resistance
  • Good resistance to chipping
  • High hardness ( > 63 HC) with high temperature tempering
  • Excellent dimensional stability during heat treatment
  • Excellent workability and recctivability
  • Excellent surface treatment properties

This steel produced by Uddeholm, the Sleipner is a fantastic carbon steel with excellent qualities of resilience and tightness of the wire, it can be simplified by saying that it is a steel similar to D2, but with all the increased parameters.

Uddeholm Sleipner

  • Abrasive wear resistance 50%
  • Adhesive wear resistance 30%
  • Ductility/resistance to chipping edges 25%
  • Toughness/chipping resistance 25%

Cold Machining Reference Class (D2)

  • Abrasive wear resistance 55%
  • Adhesive wear resistance 25%
  • Ductility/resistance to edge chipping 20%
  • Toughness/chipping resistance 10%

Sleipner Steel

Chemical composition



  • Good wear resistance
  • Good resistance to chipping
  • High hardness ( > 63 HRC) with high temperature tempering
  • Good heart hardening properties
  • Good dimensional stability during heat treatment
  • Excellent dimensional stability in operation
  • Good workability and recctivability
  • Good surface treatment properties
  • Reduced risk of chipping during wire EDM machining



  • A 6x45x475 mm Sleipner steel bar costs about 40,00 €
  • A 6x45x950 mm Sleipner steel bar costs about 80,00 €

Heat treatment tips

From my experience using the Sleipner, I found different corrosion resistance behaviors based on the heat treatment process and I made a couple of blades following the data sheets to the letter and they were less resistant to corrosion than a correction of a couple of tens of degrees less on the tempering temperature.

The reclamation that I perform at 1040 ° C followed by two findings at 480/490 ° C lasting two hours, while the technical data recommend going to 520 ° C.

As hardness from the hardness test test you can reach the peak of the curve, last blade made was 62/63 HRC but it is too much for a blade, it is not convenient to go beyond 58 HRC.

  • Hardening 1043 °C 25 minutes
  • Forced air shutdown
  • Tempering at 538 °C for 2 hours and cooling in calm air or Tempering at 555 °C for 2 hours for hardness of 58 HRC
  • Hardness obtained: 62 HRc

As maintenance a drop of oil and so far no trace of corrosion.

Sleipner is an excellent steel, it falls into the category of D2 steels that is, if you want to improve the toughness of the Sverker 21 alias AISI-D2 (they are UDDEHOLM steel names) you switch to Sleipner maybe you lose a little wear, at least 1% of Vanadium the D2 has it, against 0.5% of the Sleipner.

But it is not stainless as D2 is not, these steels have between 9% and 12% chromium is true, but it is “eaten” completely by carbon which is usually over 0.9% high – 1.5%.

Chromium serves in this case to form carbides and thus give resistance to wear, not to protect the matrix from iron oxide, this must be clear.

The beautiful M390 by Bohler is stainless and what should not be forgotten is a PM(powder metallurgy)that is made with powder metallurgy.

The letters PM mean “powder metallurgy”, a process in which molten metals are atomized into small particles, which solidify and form a fine powder that is then heated under pressure to form an ingot.


Perhaps the Sleipner loses in toughness, but it wins for wear resistance, therefore a better thread seal.

Toughness can be considered as the ability to absorb energy and deform plastically before breakage.

Corresponds to the area below the tension/deformation curve; in this case, its physical meaning is that of an energy density (international units of measurement: J/m3) stored in the material.

It can also be referred to as the property that indicates fracture resistance in a material in the presence of notches.

It should not be confused with resilience, which refers only to the elastic phase (to low deformations), and not to the entire resistance field (classically composed of elastic phase, yield strength, and plastic phase).

The value is determined by the integration of the deformation energy along the curve by drawing a vertical line from the end point of the curve to the abscis axis.

Poor toughness of a material can lead to a brittle breakage that takes place in the following stages:

  • Triggering a clique (local breakage)
  • Propagation of the break (if the material is devoid of toughness the break proceeds quickly and with a minimum expenditure of energy).

The toughness of a material is not an intrinsic characteristic of a material but depends on the test conditions, for example the deformation rate and temperature, and the defects present in the sample, for example the notches.

So based on the use of the knife is an aspect to consider.

Comparison with other acronyms of alternative steels

  • AISI D2 – W.Nr. 1.2379 – X155CrVMo12.1
  • Uddeholm – Sverker 21
  • Bohler – K110


  • Steel X90CrMoV8.2
  • Uddeholm – Sleipner
  • Bohler – K340



This steel produced by Uddeholm, the Sleipner is a fantastic carbon steel with excellent qualities of resilience and tightness of the wire, it can be simplified by saying that it is a steel similar to D2, but with all the increased parameters.

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Andrea F

Maker and Enthusiast of Knifemaking. Other: Engineer / Professional Blogger / Bass Player / Instructor of Boxing / Muay Thai / Brazilian Jiu Jitsu / Grappling / CSW / MMA / Self Defence / FMA / Dirty Boxing / Silat / Jeet Kune Do & Kali / Fencing Knife / Stick Fighting / Weapons / Firearms. Street Fight Mentality & Fight Sport! State Of Love And Trust!


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