HAP40 is the steel that defines Gihei - a powdered high-speed semi-stainless alloy that Atsushi Hosokawa and his son have been working at their Sanjo City shop since taking over a business established in 1928. CKTG has called it Voodoo Steel for years because the edge retention is genuinely difficult to believe until you experience it. At 65-66 HRC it holds an edge three to five times longer than traditional carbon or stainless alternatives, meaning less time at the stones and more time cooking. HAP40 is semi-stainless - highly resistant to corrosion under normal kitchen conditions without giving up the edge characteristics of carbon steel.
The santoku is the compact all-purpose knife in the HAP40 line, in a format that suits home cooks and professionals who prefer a shorter blade. San mai construction with stainless cladding keeps the blade road low-maintenance. The geometry is notably thin - reviewers describe it as approaching laser territory with near-zero wedging. At this thinness, HAP40 delivers extraordinary food release and slicing performance. The oak octagonal handle with urushi lacquer finish gives the knife a traditional Japanese aesthetic that the performance more than supports.
What Customers Are Saying: One reviewer rated it across five categories: edge retention 5+ (exceptional even for HAP40), wedging nearly 5 (thin geometry approaching laser levels), food stickiness 2 (a trade-off of the thin grind), sharpening difficulty 3+ (HAP40 takes more patience than carbon but rewards the effort), and profile a solid 4. Another reviewer calls the Gihei a new feeling - it arrived extremely sharp and cuts like nothing he has used before, and he can hardly believe how it performs.
Care Instructions: HAP40 is a semi-stainless steel - highly stain-resistant under normal kitchen conditions. Hand wash and dry after each use. Avoid the dishwasher. Use wood or rubber cutting boards. Avoid bones, frozen foods, and hard materials. Sharpen on quality water stones - HAP40 at 65-66 HRC sharpens more readily than its hardness suggests and responds well to stropping between sessions. The extraordinary edge retention means sharpening sessions are less frequent than with any other steel in the lineup.Blacksmith: Atsushi Hosokawa
Workshop: Gihei
Location: Sanjo City, Japan
Founded: 1928
Construction: San Mai
Edge Steel: HAP40 PM Semi-Stainless (Hagane)
Cladding: Stainless Steel (Jigane)
HRC: 65-66
Edge Grind: Even (50/50), Double Bevel
Handle: Octagonal Oak, Burnt Urushi Finish
Weight: 4.4 oz (124 g)
Blade Length: 170 mm
Total Length: 305 mm
Spine Thickness at Base: 2 mm
Blade Height: 46 mm
The santoku is the compact all-purpose knife in the HAP40 line, in a format that suits home cooks and professionals who prefer a shorter blade. San mai construction with stainless cladding keeps the blade road low-maintenance. The geometry is notably thin - reviewers describe it as approaching laser territory with near-zero wedging. At this thinness, HAP40 delivers extraordinary food release and slicing performance. The oak octagonal handle with urushi lacquer finish gives the knife a traditional Japanese aesthetic that the performance more than supports.
What Customers Are Saying: One reviewer rated it across five categories: edge retention 5+ (exceptional even for HAP40), wedging nearly 5 (thin geometry approaching laser levels), food stickiness 2 (a trade-off of the thin grind), sharpening difficulty 3+ (HAP40 takes more patience than carbon but rewards the effort), and profile a solid 4. Another reviewer calls the Gihei a new feeling - it arrived extremely sharp and cuts like nothing he has used before, and he can hardly believe how it performs.
Care Instructions: HAP40 is a semi-stainless steel - highly stain-resistant under normal kitchen conditions. Hand wash and dry after each use. Avoid the dishwasher. Use wood or rubber cutting boards. Avoid bones, frozen foods, and hard materials. Sharpen on quality water stones - HAP40 at 65-66 HRC sharpens more readily than its hardness suggests and responds well to stropping between sessions. The extraordinary edge retention means sharpening sessions are less frequent than with any other steel in the lineup.
