Cheefarcuut 400 vs FSK 400 on ZDP189 - from EdgeWorks Knife Studio

EdgeWorks Knife Studio is a sharpening-focused YouTube channel that does exactly the kind of testing forum knife nerds care about: freehand work on real kitchen knives, microscope shots of the bevel, and honest commentary on how stones actually feel in use.

In this video, EdgeWorks Knife Studio puts two 400-grit diamond stones head-to-head: the Cheefarcuut 400 sintered diamond and the FSK 400 vitrified diamond. Both are tested on a brutal proving ground — a ZDP189 Bunka at around 68 HRC — to see how they compare in speed, deburring, edge quality, and long-term usability.

Video review

Test setup

• Knife: ZDP189 Bunka, ~68 HRC – a very hard, abrasion-resistant steel that quickly exposes weaknesses in stones.
• Stones: Cheefarcuut 400 (sintered diamond) vs FSK 400 (vitrified diamond), both labeled 400 grit.
• Method: The edge is dulled, then sharpened first on the Cheefarcuut 400 and tested. The knife is dulled again and the process repeated on the FSK 400.
• Evaluation: Sharpening speed, burr formation and removal, cutting tests on paper and free-hanging paper towel, plus microscopic edge inspection.

Cheefarcuut 400

• Speed & bite: Cuts very fast and raises a burr quickly, even on hard ZDP189. After stropping, it delivers an edge that cleanly slices both regular paper and free-hanging paper towel.
• Feel & behavior: As a sintered stone, it is more porous and “thirsty,” wanting plenty of water during use.
• Wear & maintenance: The stone will dish over time. In the review, a shallow dish was visible after roughly 100 knives, meaning regular flattening is needed for heavy users.
• Value: At around USD $99, the reviewer considers it excellent value: a very capable, fast 400-grit diamond workhorse at a budget-friendly price.

FSK 400

• Speed: Feels denser, harder, and smoother in use. In this test it appears to cut at least as fast, if not faster, than the Cheefarcuut 400.
• Edge quality: Produces an even cleaner, smoother edge under the microscope, while still easily slicing paper and free-hanging paper towel after proper deburring and stropping.
• Deburring: The reviewer notes noticeably better deburring behavior on “stubborn” steels like ZDP189, making it easier to hit a crisp, clean apex.
• Water behavior: The vitrified bond is not water-thirsty and doesn’t soak or retain much water, making it more convenient to grab and use.

Durability & maintenance

• Cheefarcuut 400: Will eventually require flattening, especially with heavy or careless use. The test stone shows visible dishing, though it still performs well.
• FSK 400: Described as extremely solid and dimensionally stable. For normal personal use, flattening is rarely needed, and it isn’t prone to soaking or storing water.

Value & conclusions

• Cheefarcuut 400: A fantastic budget option that “does it all” — fast, aggressive cutting and very sharp working edges on high-hardness steels, at a fraction of the price of premium vitrified stones.
• FSK 400: At nearly USD $500 including tariffs, it is a serious investment. However, the reviewer feels it edges out the Cheefarcuut thanks to higher speed, smoother edge finish, better deburring, significantly longer life, and lower maintenance.
• Who should buy what?
  • Cheefarcuut 400: Ideal for sharpeners who want maximum performance per dollar and don’t mind doing regular flattening.
  • FSK 400: Best for enthusiasts and pros who can justify the cost and want a lifelong, low-maintenance 400-grit vitrified diamond stone for hard steels like ZDP189.

Watch the full review

For all the details, microscope footage, and live sharpening footage, watch the full video here:
Full YouTube review – Cheefarcuut 400 vs FSK 400 on ZDP189