Are these carbide knives?

[TheDuck808]

I pulled these knives out of an antique Robland thicknesser that I am in the process of restoring.

They seemed dull and I tried honing them with some water stones, but that didn't seem to do anything other than unmask a clear difference in appearance between the metal of the edge and body.

Did I luck into a set of carbide cutters on this thing? There are no markings on them that I can find.

knife1.jpgknife2.pngknife3.png

[BMKal]

Certainly look like carbide cutting edges to me. Wish I could find a set like that for my (Chinese made) thicknesser.

[DJ’s Timber]

As quoted here, they’re likely a set of Tungsten inlayed blades

These carbon steel blades are inlayed with W18Cr4V (T1) tungsten alloy, providing extra hardness and durability on the cutting edge, making them particularly suited to hard or abrasive timbers.

[Avondale]

Agree all round
My French machine has identical looking blades
20 x 2.5mm
Couldn't get 2.5 replacement, thankfully 3mm fits with no side effects