• Santoku 155mm Corrax Stainless SanMai Apex Ultra Core
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – detail view
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – side profile
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – handle detail
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – blade close-up
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 6
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 7
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 8
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 9
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 10
  • Santoku 155mm Corrax Stainless SanMai Apex Ultra Core – view 11
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Santoku 155mm Corrax Stainless SanMai Apex Ultra Core

Santoku 155mm Corrax Stainless SanMai Apex Ultra Core

By Marco Guldimann

No longer available

Marco Guldimann

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Very few knives boast the level of fit and finish that can be found in a Guldimann forged blade like this. Every step has been scrutinized for the absolute best performance, from the scientific analysis and testing of the steels grain structure, selection of cladding material, heat and cryo treatments, geometry and even techniques used in forging that increase carbon retention and improve grain structure.

This is something else altogether.

Apex Ultra clad in Uddeholm Corrax stainless steel. The cladding material and the core steel has been tested using Ultrasonic Contact Impedance to ensure that every inch of the blade has a homogeneous hardness quality throughout. The cladding is a consistent 40HRC and the core is 65HRC.

Precision convex ground and sharpened using using custom water cooled grinders and state of the art NOWI PRO guided sharpening on Japanese whetstones to achieve an absolutely consistent bevel, which is set at 16 degrees for a razor sharp and fine cutting edge.

Marco has completed this beautiful piece of precision craftsmanship with black and white ebony. Stunning hand engraved textures on the white ebony bolster, incredible fit and finish on the leather lined saya and absolutely perfect fit and finish on every detail.

Product Specification
  • Blade Type:
  • Edge Length: 155mm
  • Spine Heel: 3.75mm
  • Spine Mid: 1.69mm
  • Spine Tip (20mm before): 1.1mm
  • Blade Height: 55mm
  • Weight: 156g
  • Cutting Edge Steel:
  • Steel class: Carbon
  • HRC: 65
  • Blade Construction:
  • Blade Finish: Textured, Acid Etched (Forced Patina)
  • Grind:
  • Handle Construction:
  • Handle Materials: Black, White Ebony
  • Handedness: Ambidextrous
  • Saya / Storage Included: Yes

Blade type

Santoku

三徳

A shorter, lighter all-purpose knife — usually 165 to 180 mm — built around the same "three virtues" the name describes: meat, fish, and vegetables. The edge is flatter than a gyuto's, with a rounded, sheepsfoot-style tip, favouring a straight up-and-down push cut over a rocking motion. Its compact length and modest height make it easy to control, which has made it the default home-kitchen knife across much of the world.

The santoku trades reach and tip precision for manageability. The flatter profile and shorter blade suit smaller hands, smaller boards, and cooks who chop rather than rock, but those same dimensions limit it on large proteins and tall vegetables where a longer, taller blade does the work more easily. Think of it as a gyuto's more approachable counterpart rather than a replacement.

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 (ApexUltra project — developed by Larrin Thomas, Marco Guldimann and Tobias Hangler; FFG-funded, associated with Messerschmiede Hangler)

Apex Ultra is one of the most carefully engineered non-stainless kitchen knife steels in modern circulation — a steel designed from the ground up specifically for handmade knives, rather than borrowed from another industry. It was developed by metallurgist Larrin Thomas together with smiths Marco Guldimann and Tobias Hangler. It is a low-alloy carbon steel — roughly 1.25 percent carbon, 2.6 percent tungsten, 1.5 percent chromium and a 0.4 percent vanadium addition, with manganese and silicon kept low. That composition is tuned for high purity and a fine, evenly distributed mix of chromium-enriched iron carbides, tungsten carbides and vanadium carbides — the structure that lets it hold a very hard edge without the coarse carbides or plate martensite that sap toughness in other high-hardness carbon steels.

What this means for a cook is unusual permission. Apex Ultra carries very high toughness in the 66+ HRC range — the highest of any knife steel its developers have tested at that hardness — so you can ask a maker to grind it thin and run the heat treatment hard, and the edge will hold far longer than the carbon steels smiths usually forge, without microchipping. It forges and forge-welds much like 52100 or 1.2562, sharpens cleanly on natural and synthetic stones without needing diamond plates, and its modest chromium slows patina a little — though it is not stainless and should be cared for 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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