Knife blade hardening service

DICTUM - Hardening Service

We offer customers a qualified blade hardening service (up to 100 cm). Optionally, you can choose to receive an original test certificate with the exact hardness value of the cutting edge in HRC (Rockwell).

This will give you a clear understanding of the actual end hardness of your blade after hardening. We harden all conventional stainless and non-stainless blade steels using the vacuum procedure (DIN-certified).

This is how it works:

  1. Print order form
  2. Shape your blade and pre-grind it to grit 150
    (the blade should still be 0.5 mm thick).
  3. Draw the outline of your knife blade on a sheet of paper
    (to keep track of the blade after hardening).
  4. Send us your knife with the outline drawing and information on the material as well as, if relevant, instructions for how to harden it
    (hand it in at one of our branches or mail it to us, using one of our special boxes (No. 909080) if required.
  5. We will return the hardened knife blade with the test certificate and spherical indention images within about 2-3 weeks of receipt.


Important Note!

  • We recommend grinding the blade only up to a maximum grain of 150 before hardening.
  • The blades should not be sharp before hardening, but should have a material thickness of at least 0.5 mm at the cutting edge!
    Otherwise, there may be severe hardening distortion at the cutting edge.
  • Please note that the blades are subjected to extreme structural changes during hardening and that all stresses in the steel structure are discharged.
    In some cases this can mean a crooked blade, in rare cases a broken blade. This usually only applies to forged blades. We therefore recommend that you heat treat forged blades before hardening.
  • Blades made of flat material should not have blued during grinding. If there are blue areas, we recommend that you anneal the blade with low stress before hardening in order to avoid hardening distortion.
  • We do not assume any warranty for hardening distortion or breakage! Despite the greatest care, we cannot completely compensate for forging errors by heat treatment. In a few cases, blades may warp despite optimal heat treatment.
  • We do not offer cryogenical hardening!
  • We harden all blades in high-performance hardening oil.
  • No tape on the blade! This can cause damage to the surface.


Download order form (PDF)Download order form (PDF)


Fee for the hardening service with test certificate: € 54.90 (incl. VAT, excl. delivery fee).

Fee for the hardening service without test certificate: € 45.00 (incl. VAT, excl. delivery fee).

DICTUM - Hardness Test

Have you always been curious about the hardness of your finished knife blade? If so, you can use this service to get us to test the hardness (HRC) of your knife blade at its cutting edge. Heat treatment shops generally only perform HRC tests on the tang or back of the blade. However, testing these areas does not provide any reliable information about the hardness of the blade itself. Performing an HRC test at the cutting edge would destroy the blade.

Hardening test blade

This is why we use the Vickers hardness test, which uses very low test pressures and allows us to test a blade’s hardness right at the cutting edge without destroying it.
This method simply involves minimal grinding of the cutting edge, which is then returned to its original state after the test. On completion, you will receive a test certificate with spherical indention images and the Vickers values converted to HRC.

Download order form (PDF)Download order form (PDF)


Fee for the hardness test with test certificate: € 15 (incl. VAT, excl. delivery fee).

Hardening test detail