When a knife enters the four-figure luxury price bracket, it naturally sparks a lot of questions. Rockstead is famous for pushing production cutlery to its absolute limits, and the Ritsu ZDP-GD fixed blade is one of their most stunning creations.
To help you decide if this high-performance Japanese tool is right for your collection, we have compiled the ultimate Frequently Asked Questions guide covering its design, steel composition, maintenance, and purchasing details.
Core Product & Design FAQs
What does the "GD" stand for in the Ritsu ZDP-GD model name?
The "GD" designation stands for Gold. It indicates that this specific variant features a hand-contoured guard and backplate machined from lightweight titanium and finished with a striking, understated gold anodization. It contrasts beautifully with the dark handle scales.
What handle materials are used on the Ritsu?
The handle scales are made from premium Wood Micarta. This high-end composite material is created by compressing wood fibers and phenolic resin under immense pressure. It delivers the rich, warm look of natural wood grain but is entirely impervious to water, sweat, humidity, and temperature warping.
What are the exact dimensions and weight of the knife?
The Ritsu is designed to be a highly capable, compact fixed blade:
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Overall Length: 8.39 inches (213 mm)
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Blade Length: 3.74 inches (95 mm)
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Blade Thickness: 0.15 inches (3.7 mm)
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Weight: 4.33 ounces (123 grams) without the sheath.
Steel, Hardness, & Performance FAQs
What steel is used in the blade, and what is its hardness?
The core cutting edge of the Ritsu is forged from ZDP189 powder metallurgy super-steel. Rockstead heat-treats this core to an incredible hardness rating of approximately 67 HRC (Rockwell Hardness). This is significantly harder than standard high-end production knives, which usually top out around 60–62 HRC.
Since the steel is so hard, isn't it brittle? How does it avoid chipping?
Rockstead solves the potential brittleness of 67 HRC steel through two brilliant engineering choices:
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Clad Steel Structure: The brittle ZDP189 core is sandwiched between two layers of more flexible, supple VG-10 stainless steel. The VG-10 acts as a shock absorber for the blade.
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Honzukuri Grind: Instead of a flat primary bevel, the blade features a continuous, dual-convex edge geometry.
As seen in the technical diagram above, a convex grind curves outward. This architecture leaves a massive amount of supportive steel right behind the microscopic cutting apex, giving it the strength needed to prevent micro-chipping under stress.
Why is the blade polished to a mirror finish? Is it just for looks?
While it looks beautiful, the mirror finish serves a vital performance purpose. Rockstead hand-polishes the blade to a surface roughness of less than 0.1 micrometers. By wiping away the microscopic ridges left by grinding wheels, they drastically reduce friction during slicing and deny moisture a place to hide, significantly increasing corrosion resistance.
Maintenance & Sharpening FAQs
How often does the Ritsu ZDP-GD need to be sharpened?
Under normal Everyday Carry (EDC) or light outdoor usage, the combination of a 67 HRC ZDP189 core and a Honzukuri convex grind allows the knife to maintain its razor-keen factory edge for two to three years without needing a formal sharpening.
Can I sharpen this knife myself at home?
We highly advise against sharpening it on standard flat whetstones or electric systems. Doing so will flatten out the precise Honzukuri convex geometry and ruin the mirror finish. For basic edge maintenance, you should only use a smooth leather strop with fine diamond paste, following Rockstead’s official guidance.
What happens if the blade finally goes dull or chips?
Every genuine Rockstead knife comes with access to their lifetime factory sharpening and restoration service. When your knife needs a refresh, you can send it directly back to the Rockstead workshop in Sakai, Japan. Their master bladesmiths will regrind, re-polish, and restore the blade to its exact original factory-new specifications (you only cover the shipping fees).
Purchase & Logistics FAQs
Why should I buy the Ritsu ZDP-GD from an authorized platform like EDC Mall?
Because Rockstead knives are major financial investments, buying from a trusted, authenticated dealer like EDC Mall ensures:
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You receive a 100% genuine knife (counterfeits do exist on the market).
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The knife comes with its individual serial number and official Certificate of Authenticity.
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Your proof of purchase is valid for registering the knife on Rockstead's official portal, which is mandatory to qualify for the free lifetime factory sharpening service.
Does it come with a sheath?
Yes. The Ritsu comes with a premium leather belt sheath. To prevent the ultra-sharp edge from cutting through the leather, Rockstead builds a rigid Kydex liner directly inside the sheath, combining traditional luxury aesthetics with modern physical safety.
