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Hon-Tajima Natural Whetstone #21097

Hon-Tajima Natural Whetstone #21097

$320.00 USD
$320.00 USD
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dimensions

• Length: 8-1/4 " (210mm)
• Width: 3-1/8"(80mm)
• Height: 2-1/4"(56mm)
• Weight: 5.2Lb (2368g)

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


Overview


An authentic, vintage Tajima Toishi (Hon-Tajima) sourced from the defunct quarries of Hyōgo Prefecture, Japan. Functioning as a traditional medium-grit stone (Chu-toishi, ~#800–#2,000 grit), Tajima is prized among blade sharpeners and woodworkers for yielding a fast, creamy slurry that produces a clean pre-polish and rich kasumi haze on clad steel bevels.  
At over 5.2 lbs and full bench length, this massive block provides a wide, stable sharpening platform capable of handling large kitchen knives (gyuto, yanagiba) and broad woodworking plane irons (kanna).  


Specifications


Type: Japanese Natural Whetstone (JNAT) / Medium Grit (Chu-toishi)  
Origin: Tajima (但馬), Hyōgo Prefecture, Japan  
Markings: Prominent boxed Honba Tajima To (本場但馬砥) regional provenance stamp and side inspection seal  
Dimensions: 8-1/4" × 3-1/8" × 2-1/4" (210 mm × 80 mm × 56 mm)
Weight: 5.20 lb (2,368 g)


Condition & Visual Details


Stamps: Clear, bold black-ink provenance stamp (Honba Tajima To) on the face and secondary oval inspection mark on the side.  
Matrix & Color: Pale greenish-ash volcanic body showing handsome golden-brown/tan oxidation and natural mineral staining across the sides and top.  
Shape & Cut: Oversized bench block with an angled trapezoidal profile and prominent quarry saw ridges across both primary faces.  
Flaws: Notable diagonal corner breakout/loss at one end, natural edge chippy areas, and raw quarry surface grooves (sold unlapped as-found).  

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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