Whetstones

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

Brand: Naniwa ナニワ研磨工業
Stone Length: 270mm
Stone Width: 70mm
Stone Height: 10mm
#1000 Grit Stone Weight: 315g
#3000 Grit Stone Weight: 297g

Soaking Requirement: Several minutes

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

"Base" series; Does NOT include base

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

Please Note: These pictures and measurements are examples. Your specific product may differ slightly in appearance and measurements.

Oboro Knife

The newest NSK series, Oboro Knife was designed specifically for kitchen knives, and are very effective on a wide variety of steels for a wide variety of services. The abrasives in Oboro Knife tend to cut deeper and faster than other NSK lines, thus they are the most ideal series for full-blade servicing such as thinning, repairing, and reprofiling. Ideal for seasoned to advanced users.

Oboro Knife grits are: 200, 400, 800, 2000, 4000, 6000

Brand: NSK Kogyo Ltd.
Grit Range: #4000
Thickness: 3.5mm
Length: 200mm
Width: 75mm
Height: 26.5mm
Weight: 740g

Oboro Knife

The newest NSK series, Oboro Knife was designed specifically for kitchen knives, and are very effective on a wide variety of steels for a wide variety of services. The abrasives in Oboro Knife tend to cut deeper and faster than other NSK lines, thus they are the most ideal series for full-blade servicing such as thinning, repairing, and reprofiling. Ideal for seasoned to advanced users.

Oboro Knife grits: 200, 400, 800, 2000, 4000, 6000

Brand: NSK Kogyo Ltd.
Thickness: 3.5mm
Length: 200mm
Width: 75mm
Height: 26.5mm
Weight: 740g
Grit Range: #6000

Flattening Stones

Although all NSK stones are very wear resistant, these flattening/dressing stones are specifically formulated to counter the wear resistance and flatten at an impressive speed. They also work very well on natural stones as well, and the higher grit flattening plates will leave a scratch-free surface unlike many other diamond plates. The flattening stones are slotted to eliminate suction when rubbing against the sharpening stone.

If needed, coarser flattening grits can initially be used on higher grit sharpening stones to remove material quickly, as long as you condition the surface of the sharpening stone with a higher grit flattening plate before use in order to prevent overly-aggressive surface. Each grit of the flattening stones can be used on several different grits, so there is no need to get every single flattening grit for each corresponding grits of NSK sharpening stone you may have; see recommended grit ranges for each flattening stone below.

Flattening grits: 200, 400, 600, 1000, 3000, 6000

Recommended Use: Flattening grits from 200-1000 can be used on All NSK sharpening stones up to 1500 grit. All NSK sharpening stones with grits above 1000 should ideally be flattened with a grit as close to the stone's grit as possible. For example, a 3000 grit sharpening stone should be flattened with grits 3000 and above.

Brand: NSK
Length: 200mm
Width: 75mm
Height: 17mm
Weight: 468g
Grit Range: #600

Grit: #10000
Case Length: 240mm
Case Width: 80mm
Case Height: 35mm
Stone Length: 210mm
Stone Width: 70mm
Stone Height: 15mm
Total Weight: 713g
Nagura Included: No

Brand: Tanaka Toishi 田中砥石工業所
Producing Area: Mikawa Mountain Range, Kitashitara, Aichi - Japan
Mine: Kada Mountain or unspecified Junmikawa stratum
Strata: N/A
Appearance: "Striped" (shima) lines running linearly down the length of the stone, a mix of off-white and orange. Beautiful chalky block!
Size: 220mm x 82mm x 45mm
Weight: 1573g
~Grit Range: 2500-4000

1-5 Scale: 1 = Less, 5 = More
Hardness Level: 3.5
Scratch Depth: 2.5
Speed: 2 (4 with tomo nagura)
Wear Rate: 2
Self Slurry: 2 (4 with tomo nagura)
Thirst: 3
Consistency: 3.5
Feedback: 2.5
Ease of Use: 2.5

Notes: A large, pure nagura that will last many years. 

Suggested Use: pre or final polisher for knives and push-cut tools.

Background Info: Nagura are made of lithified tuff, which is silica-rich stratified volcanic ash that has been compacted into a solid over many, many years, and this composition yields unique sharpening and polishing properties. Much of their use has been centered around blades other than knives: swords, razors, woodworking tools and so on. Nagura can come from several locations in Japan, the most famous being the Junmikawa (Mikawa) mine located within the Mikawa Mountain range in Aichi Prefecture. 

Chu Nagura are used as one of the last stones before Uchigumori in a traditional sword polishing sequence. Such "proper" Chu Nagura are mined at Kada Mountain, not from the Mikawa mine-proper, both of which are in the same mountain range. Chu Nagura can also be somewhat of a catch-all term for stones from the Mikawa mine that do not fit cleanly into the known classified strata. Within swords, "chu" is often used to roughly mean "medium" (medium grit, medium size, etc.)

Please Note: Given the natural aspect of these stones, all subjective qualities are our estimates and may vary slightly from your exact expectations and assessment. The images shown and characteristics described may be from a previous example. If purchased, yours may differ slightly in appearance and qualities. Dimensions, weight, and stamps may be different from listed if it has been tested.