High-grade steel designed for hardened tools with durable cutting edges, such as knife blades, surgical cutting instruments, circular blades for the meat industry, skate blades, etc.

690 steel is manufactured in Austria by Böhler using hot rolling. It is excellent for machining and grinding, even after hardening. If the steel is heat-treated correctly, ideally at precise temperatures in a vacuum hardening furnace, and tempered, it achieves very good mechanical properties at the cutting edge. A hardness of around 60–61 HRC after correct hardening meets most of the expected requirements for normal to moderate blade stress. However, if the steel is drawn at a shallow angle practically into the cutting edge, it becomes very susceptible to chipping. If you chop with such a blade, you will certainly destroy it.

The steel is highly resistant to corrosion, due to its high chromium content. It is therefore very often used for kitchen and hunting knives. Specifically with hunting knives, the blade is only treated after a considerable period of use, which is why hunters appreciate this property.

N690 polishes very easily and well, and a mirror-like shine can be achieved. This steel is easily recognisable by the clusters of carbides visible after polishing, which form characteristic grids visible to the naked eye.