Jay Fisher - Fine Custom Knives

"Sonoma" Chef's/Working Knife

• Size: Length overall: 10.6" (27 cm), Blade Length: 6.5" (16.5cm), Thickness: .139" (3.5 mm)
• Weight: Knife: 7.0 oz. (198 grams), Leather Sheath: 6.6 oz. (187 grams), Locking Kydex Sheath: 11.6 oz. (329 grams)
• Blade: 440C High Chromium Martensitic Stainless Tool Steel, Hardened and Tempered, T3 Specialty Cryogenically treated to Rockwell C58, mirror polished
• Bolsters/Fittings: 304 High Nickel, High Chromium Austenitic Stainless Steel, mirror polished
• Handle: Pilbara Picasso Jasper Gemstone (Australia)
• Sheath: Heavy 9-10 oz. thick leather shoulder, hand-stamped, burgundy, lacquered
• Sheath: Locking (Version 2.0) in Black Kydex, Black Anodized Aluminum Alloy, Blackened Stainless Steel, 6AL4V Titanium

• Knife: The name Sonoma means "valley of the moon," where the author Jack London, who had a ranch there, popularized the Native American word Sonoma. In the heart of wine country of California, Sonoma the knife envisions the beauty, elegance, grace, and function of a fine cutting instrument. The Sonoma pattern was designed with direct input from professional chefs for use in the kitchen as well as being designed as a working knife and tool. This is a true "dual duty" knife.;
  • Blade steel: I made the Sonoma blade in hypereutectoid, high alloy stainless tool steel, 440C. This is my most requested steel for a reason, and that reason is—when properly treated and finished—this steel has the highest corrosion resistance possible, while being tough and wear-resistant. It's a proven performer suited for the kitchen, and in the field, and it's clean, slick, smooth, and dependable. 440C is extremely high in chromium, and that contributes to the other elements that make it a great steel. First, the carbon in this steel is extremely high at 1.25 percent, allowing significant development of martensite and forming of essential iron carbides. The second element is chromium, and at 18 percent, this is a highly corrosion-resistant stainless steel. High chromium also creates extremely hard and durable chromium carbides adding to the wear resistance and overall strength and stability of the steel alloy. The third transformational element is molybdenum. 440C has 0.5% molybdenum, which doesn't seem like a lot, but in this case the molybdenum provides significant nucleation sites for the formation of all carbides in the steel: iron carbide, three types of chromium carbides, molybdenum carbide, and combination carbides of all three elements. Molybdenum helps precipitate these carbides at critical dislocation and grain boundary areas of the crystalline structure, stabilizing the structure against fracture, toughening it. Toughness is resistance to breakage, and this allows a very thin cutting edge and blade geometry with high corrosion resistance. This means a thin, sharper, tough, corrosion-resistant blade. Consider that a chef's knife can dull by exposure to acidic, chemically aggressive foodstuffs, dulling lesser blades, and the importance of corrosion resistance is clear. Add to this that because 440C can be kept critically clean, it is ideal in the kitchen.
  • Heat Treatment: This Sonoma has my New T3 heat treatment, yielding an astounding blade in incredible condition through advanced processing protocols. How advanced is this treatment? It's a multi-stage cryogenic treatment, involving temperatures ranging in over 2000°F (1090°C) to -320°F (-196°C). The process is an evolution of my advanced heat treating processes, and consists of 33 dedicated and specific steps and takes 172 hours! This means that just to heat treat this blade takes over a week! The reason for this is scientific and critical, but yields the most stable, most wear-resistant, most durable and long-lived structure of this steel, profuse with fine multi-element carbides and a uniform and unbelievably robust structure. This is a testament to my determination to make the very best knives, steels, treatments and kits in the modern world. I know of no one else who has advanced the treatment to this level; it's unheard of in the metals and knifemaking field.
  • Blade Design and Geometry: Most people would consider a chef's knife a large, wide, and lengthy blade, typical of European concepts of the French "Sabatier" design. However, nearly all of the tasks of the skilled chef are accomplished with a more pointed, thin and sharp knife. Unlike Japanese designs which are delicate and weak, the Sonoma has a considerable spine, and just enough thickness to support the hollow grind. A hollow grind can offer the lowest sharpening angle and greatest longevity of a knife that has to have a stiff, strong spine, detailed on my "Blades" page at this bookmark. The curve of the blade at the cutting edge had to be just right: thin enough for piercing, curved enough for strength. The blade is aggressive, not too wide to limit sideways-curved cuts, and long enough for nearly every task, with as low of a weight as possible while offering a rigid, tough design to support the cutting edge. The edge itself is incredibly sharp, with a low angle single-bevel cutting edge and razor-keen performance.
  • Blade Finish: The blade and bolsters are mirror polished. This is critical in the kitchen; too many knives are rough, unfinished, and unable to be cleaned in the knife field. There is no filework to trap foodstuffs, no hiding place for bacteria in the polished blade. The chromium oxide surface nature of this stainless steel easily releases all types of food and is sterile and smooth.
  • Bolsters: I bolstered the Sonoma with my signature zero-care, high nickel, high chromium 304 austenitic stainless steel bolsters, contoured and rounded for comfort of the hands, and shaped and radiused in the front face for easy cleaning. They are attached with multiple through-tang pins of 304 stainless steel, and the mounting is permanent, as well as extremely corrosion-resistant. This is the same steel used for stainless steel nuts, bolts, and fasteners, and the same steel that is used in nearly every NSF kitchen appliance and exposed surface. I bolstered the Phact with zero-care 304 high chromium, high nickel stainless steel bolsters, and they are contoured, rounded and polished for a comfortable feel. The bolsters are secured with zero-clearance peened pins and dovetailed to bed the scales. The front bolster has a wide, flat top even with the spine for applying pressure, and a bit of curve to support the forefinger and prevent it from moving toward the blade in a forward grip. The rear bolster is wide and flat, aiding in balance and filling the palm of the hand for control. It also aids in easy unsheathing.
  • Handle: The handle scales I chose for this knife are striking Pilbara Picasso Jasper gemstone. This is a beautiful, tough, and entirely hard and smooth gem from Western Australia. It's a cryptocrystalline quartz with minor inclusions of hematite. It's extremely dense and solid, perfectly easy to keep clean and will positively outlast the entire knife! The play of color and light is intense in bright sunlight, and under magnification, it's even more beautiful (see the enlarged photos below). It's polished absolutely smooth and is rounded, contoured and blends seamlessly with the handle.
  • Balance and Feel: The center of balance of the knife is at the location of the first finger, so the blade is neutral and light in the hand. The handle shape, the thumb rise on the top of the spine, and the drop in front of the blade prevent the hand from advancing on the cutting edge. Plenty of pressure can be applied to the spine via the thumb at the thumb rise, or the forefinger on top of the smooth spine for control. The small notch in the thumb rise that engages the sheath lock is smoothed and polished and hardly noticed. The handle is lightweight and is surrounded in the palm. This is not a big, fat rounded plastic handle found in the novice kitchen knife. The combination of handle and blade creates a cutting instrument, light, elegant, and effective.
• Leather Sheath: I've included a heavy, tough, and solid leather sheath for the Sonoma in 9-10 oz. leather, hand-stamped and tooled. The leather is shoulder, from mature cows, and is twice as thick as most other knifemakers use. The stamp-tooling is a tri-basketweave pattern, and I've dyed the leather a deep burgundy to match the gemstone handle. The sheath has a belt loop that is double-row stitched throughout with the tough nylon thread. The knife fits deep and secure into the sheath, with the handle exposed and the high back of the sheath protecting the wearer. The sheath edges are dressed and smoothed for comfort; the entire sheath is sealed with lacquer for water resistance, permanence, and longevity. The leather sheath is great in a more casual setting when a knife simply needs to be a tool.
• Locking Sheath: The locking sheath (Version 2.0) I've made for this kit is a professional assembly, and frankly, the best tactical sheath and accessory package made in the world. It's also an example of my commitment to making the finest combat tactical, and rescue knives and sheaths on the planet. It starts with double thickness (.125") kydex (methyl acrylate and polyvinylchloride), hot-formed over an aluminum welt frame of 5052 high strength corrosion resistant aluminum alloy in H32 hardness. The high alloy aluminum I've anodized and permanently dyed black, creating an near-ceramic hard coating 1 mil thick on the surface of all of the aluminum, inside and outside of the metal, whether exposed or not. This brings the aluminum to its highest, most durable condition. Even my dying procedure for the anodizing uses sunlight-stabilizing surface sealing for the greatest colorfastness of the hardened surface. The body and welts are secured with media-blasted and slotted 304 stainless steel Chicago screws for the ultimate in durability with no care and no glare, all blackened to match with a passive oxide surface.
• An excellent knife for the kitchen, for carry and wear, for working chores, elegant in function, premium in materials, beautiful in finish.

Thanks S. H. and B. W.!