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Hon-Tajima Natural Whetstone #13987

Hon-Tajima Natural Whetstone #13987

$335.00 USD
$335.00 USD
Sale Sold out
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dimensions

• Length: 8-1/4 " (210mm)
• Width: 3-1/8"(80mm)
• Height: 2-1/4"(56mm)
• Weight: 5.47 lb (2486g)

 Hon-Tajima Natural Whetstone (天然但馬砥石)  


Overview
An authentic, vintage Tajima Toishi (Hon-Tajima) quarried from the defunct mines of Hyōgo Prefecture. Classified as a classic medium-grit whetstone (Chu-toishi, ~#800–#2,000 grit), Tajima is renowned for generating a fast, creamy slurry that produces a clean pre-polish and a rich kasumi haze on clad kitchen knives and woodworking tools.  
Weighing nearly 5.5 lbs with a wide, generous footprint, this heavy block provides ample surface area for full-sized blades (gyuto, santoku, yanagiba) and wide plane irons (kanna).

 
Specifications
Type: Japanese Natural Whetstone (JNAT) / Medium Grit (Chu-toishi)  
Origin: Tajima (但馬), Hyōgo Prefecture, Japan  
Markings: regional provenance stamp  
Dimensions: 8-1/4" × 3-1/8" × 2-1/4" (210 mm × 80 mm × 56 mm)
Weight: 5.47 lb (2,486 g)


Condition & Visual Details

Stamps: Bold, highly legible black framed Honba Tajima To (本場但馬砥) stamp on the top face.  
Matrix & Color: Characteristic light ash-grey/pale green volcanic matrix with uniform dark mineral inclusions.  
Shape & Cut: Heavy bench-style block featuring a slightly tapered cross-section, beveled corner, and prominent original quarry saw ridges across the working faces.  Top working surface is for the most part dead-flat and lapped in virtual ready-to-go condition.
Flaws: Notable triangular chip/step breakout on one edge, diagonal corner relief cut/loss, and light corner wear; offered in raw, as-found vintage condition.  

care instructions

​Initial Inspection & Cleaning: Before use, gently inspect your Japanese natural whetstone (JNAT) for any loose grit or debris, and wash the surface with clean water and a soft brush.
​Soaking Guidelines: Understand your specific stone's hardness; softer stones (like Aizu or Amakusa) generally require a brief soak of 10 to 20 minutes, while harder, finer finishing stones (like Tomae or Suita) often perform best as splash-and-go stones requiring only surface hydration.
​Avoiding Thermal Shock: Never submerge a cold or dry stone in hot water, and avoid exposing your JNAT to extreme temperature shifts, which can cause cracking or structural failure.
​Slurry Generation: Build a natural abrasive slurry using a diamond plate, coarse stone, or a matching nagura (such as a Tsushima Nagura) to jump-start cutting action and condition the surface for your blade steel.
​Water Maintenance: Keep the stone adequately lubricated with clean water throughout the sharpening session, periodically rinsing away accumulated swarf to maintain optimal feedback and cutting speed.
​Drying Process: After sharpening, rinse the stone thoroughly under clean running water and allow it to dry completely in a well-ventilated, shaded area away from direct sunlight and artificial heat sources.
​Long-Term Storage: Store your dried JNAT in a stable environment where it won't be subjected to heavy impacts, freezing temperatures, or high humidity fluctuations that could compromise its integrity.

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