• Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak
  • Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak – detail view
  • Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak – side profile
  • Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak – handle detail
  • Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak – blade close-up
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Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak

Gyuto 235mm GoMai Apex Ultra Integral Stabalized Bog Oak

By Jeroen Knippenberg

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Jeroen Knippenberg

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This 235 mm Gyuto by Jeroen Knippenberg is a refined handmade kitchen knife that balances technical performance with strong material presence. Forged in a 5-layer Go Mai construction with an Apex Ultra core, it is designed for serious cutting work while maintaining the visual and tactile qualities that define Jeroen’s integral pieces. The longer profile and generous blade height give the knife a composed, authoritative feel on the board, making it particularly well suited to larger ingredients, high-volume prep, and users who appreciate a Gyuto with a little more reach and substance.

At the heart of the blade is Apex Ultra, a high-performance carbon steel known for its extremely fine grain, excellent edge stability, and outstanding sharpness potential. Hardened to 66 HRC, it offers exceptional cutting performance and strong edge retention for those willing to care for a non-stainless knife properly. The acid-etched forced patina gives the blade a darker, more subdued finish while also highlighting the character of the layered construction. Over time, the blade will continue to develop its own surface character through use, reinforcing the individuality of the piece.

The geometry has been developed to support both power and control. With a spine measuring 4.67 mm at the heel, 3.15 mm at mid-blade, and 1 mm near the tip, the knife carries reassuring strength through the rear of the blade while still tapering enough to support precise, controlled tip work. The convex grind helps reduce cutting resistance and encourages improved food release, while the 56 mm blade height provides excellent knuckle clearance and a confident working platform. At 312.6 g, the knife has a notably solid feel in hand, lending stability and momentum through more demanding prep without compromising overall control.

The handle is finished in stabilized bog oak with G10 accents, bringing together durability, texture, and a restrained visual contrast that complements the darker blade finish well. The result is a knife that feels cohesive and deliberate in every detail—well suited to cooks and collectors seeking a larger-format Gyuto with elevated cutting performance, distinctive materials, and the unmistakable character of a handmade integral by Jeroen Knippenberg.

Product Specification
  • Blade Type:
  • Overall Length: 376mm
  • Edge Length: 235mm
  • Spine Heel: 4.67mm
  • Spine Mid: 3.15mm
  • Spine Tip (20mm before): 1mm
  • Blade Height: 56mm
  • Weight: 312.6g
  • Cutting Edge Steel:
  • Steel class: Carbon
  • HRC: 66
  • Blade Construction:
  • Blade Finish: Acid Etched (Forced Patina)
  • Grind:
  • Handle Construction:
  • Handle Materials: Stabilised Bog Oak, G10
  • Handedness: Ambidextrous

Blade type

Gyuto

牛刀

The Japanese take on the Western chef's knife, and the most versatile blade in a modern kitchen. A gyuto carries a long, gently curved edge — most often 210 to 270 mm — that allows both push cuts and a rocking motion, with a pointed tip for fine work and enough height at the heel to keep knuckles clear of the board. It handles proteins, vegetables, and herbs without complaint, which is why most cooks reach for it first.

Compared with a European chef's knife, the gyuto is usually thinner, harder, and lighter, ground to a finer edge that rewards good board technique and regular honing. That same thinness is the trade-off: the edge is less forgiving of bone, frozen food, and twisting cuts, and it asks for a little more care in maintenance in exchange for its keenness.

View full knife type guide →

Cutting edge steel

Apex Ultra

Low-alloy fine-grain carbon tool steel

Typical HRC
64–68
Corrosion class
Carbon
Production
Conventional
Origin
Austria (developed by Tobias Hangler and Marco Guldimann; project led by Hangler at Messerschmiede Hangler)

Apex Ultra is one of the most carefully engineered non-stainless kitchen knife steels in modern circulation, and the project of an Austrian smith — Tobias Hangler — who set out, with Marco Guldimann, to design a steel for the kitchen rather than borrow one from another industry. It carries roughly 1.25 percent carbon, around four percent chromium, modest tungsten and molybdenum, and a small vanadium addition. The composition is tuned to produce a fine, evenly distributed carbide structure that supports hardness up to 67 HRC while delivering toughness comparable to 52100 at the same hardness — a combination that is the entire point of the steel.

What this means for a cook is unusual permission. You can ask a maker to grind an Apex Ultra knife thin enough that a White #1 owner would call you brave, then ask for the heat treatment to land at 65 HRC, and the resulting edge will hold for longer than Aogami Super without microchipping. It sharpens cleanly on natural and synthetic stones alike and patinas slowly because of the chromium content, though it is not stainless and should be treated as a carbon steel.

Apex Ultra has become a signature steel of the European maker community, and the Modern Cooking catalogue carries an unusually deep bench of smiths working in it. Tobias Hangler himself heads that group, alongside Marco Guldimann, Benjamin Kamon, Martin Huber, Jonas Johnsson, Karol Karyś, Birch & Bevel, and MCx. It is genuinely a step forward — one of the relatively few cases where the marketing claims and the underlying metallurgical data are saying the same thing.

View full steel guide →

Blade construction

Laminated Steel

A category covering knives built from multiple layers of different steels forge-welded together. The hard cutting steel is sandwiched between softer outer layers (cladding) that protect the core, add toughness, and often contribute visual contrast.

The most common laminated constructions in the Modern Cooking catalogue are:

SanMai (三枚) — three layers: hard cutting steel in the centre, softer cladding on both sides. The traditional and most common form.

GoMai (五枚) — five layers: a hard core, two intermediate layers, and two outer layers. Adds visual depth and structural complexity.

KuMai (九枚) — nine layers: similar logic, with more cladding layers for additional pattern and structural variation.

GoMai and KuMai are often chosen not only for the additional layers and visual depth, but also because the intermediate layers can act as a nickel diffusion barrier — limiting carbon migration out of the core into the cladding during forge welding, and protecting the core's intended carbon content through the heat of the forging process.

In all cases the cutting performance is determined by the core steel; the outer layers are cosmetic and structural. The lamination contributes corrosion protection (when a stainless jacket clads a carbon core), reduced reactivity, and the visible boundary between core and cladding that gives the knife its character.

View full construction guide →

Grind

Convex

A grind whose bevel bulges outward in a gentle curve from spine to edge, rather than running flat. That extra steel directly behind the edge makes a convex grind notably strong and resistant to chipping, while the curved geometry helps food release and lets the blade glide through dense ingredients with less wedging than a flat grind.

The strength comes at the cost of ultimate thinness and ease of maintenance. A convex edge has more metal behind it, so it is not quite as effortlessly keen as a thinly flat-ground edge, and it is harder to sharpen freehand — holding the curve takes a stropping technique or a deliberate hand rather than a single fixed angle. The reward is an exceptionally tough, smooth-cutting edge.

View full grind guide →

Handle construction

Hidden Tang

A construction in which the tang runs into the handle but stays concealed inside it, rather than showing between two scales. A narrower tang — a full-length stick or a shorter projection — is set into a drilled or burned channel in a one-piece handle and secured with adhesive, a friction fit, or a threaded fitting drawn up against the blade. This is the traditional construction of Japanese wa-handles and many European hidden-tang knives.

The design puts the handle material in charge of the look and feel: a single piece of wood, horn, or composite — often with a ferrule or spacers at the front — is shaped into any cross-section the maker wants, from the classic octagonal and D-shaped wa profiles to fully rounded Western forms. With no steel showing along the grip, the handle can be slim and light, and is frequently made to be removed and replaced, with the balance sitting toward the blade.

View full construction guide →

Shipping & Returns

Shipping

We process orders 5 days a week (Monday - Friday) and ship from our shop in Sydney, Australia. We ship with FedEx, UPS and DHL.

We are happy to offer free international shipping on a variety of orders depending on location and order value.

Free Shipping Regions and Minimum Order Values

For Australia and New Zealand the minimum is $500AUD. For the rest of the world it is approximately €1000EUR. The discount is applied automatically when you reach the minimum cart value at checkout.

Returns

If you're not entirely happy with your purchase, you can return it within 14 days of delivery for a refund. The item must be in its original condition with all original packaging.

  • Returns are accepted for 14 days
  • The customer is responsible for return shipping costs
  • A 15% restocking fee may be applied to change-of-mind returns
  • We do not accept returns on second-hand items for change of mind

Faulty or Damaged Items

You must notify us within 5 business days of receiving your order. Photographic evidence of damage is required. Once approved, Modern Cooking will cover return shipping costs.

Product Care

Cleaning: Clean by hand with warm water. Avoid wetting the handle when possible.

Sharpening: We advise using whetstones to sharpen your knives and a honing rod or steel to maintain the burr between sharpening sessions.

Reactive Steels: Reactive steels like Aogami Super, Apex Ultra or premium reactive German and Swedish steels are susceptible to rust if not properly cared for. Keep the knife dry between uses and when storing for longer periods, wiping the blade with Tsubaki oil or another food-safe oil is a wise choice. A patina can be a beautiful personal feature on your knife and helps to stop rust forming.

Handle Care: For non-stabilised wooden handles, apply Tsubaki oil or another food-safe oil from time to time. Food-safe wax can be applied to both stabilised and non-stabilised wooden handles. Never apply hot wax or oil as you risk warping or damaging the handle.

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