Occasionally released through Konosuke’s Sakai shop, “Test Sample” knives represent experimental, one-off pieces that fall outside standard production and marking conventions.

TEST SAMPLES & PROTOTYPES Years Made 2024+ Steel Various

Marking Patterns K-F-04-NS      Test Samples K-F-04 Test Samples K-PR-01      Stainless Steel Prototype

Konosuke occasionally sells “Test Sample” knives at its Sakai shop. These are one-off pieces created while experimenting with new finishes or processes and looks to coincide with development of the KS-01, LI & BY series. Prototypes have also surfaced through select retailers.

Of the five Test Sample knives examined, only one bore the Sakai kanji chiseled on the blade. While the stainless steel prototype shown below breaks from the standard marking pattern with the Konosuke stamp on the right face.