The 1x4 Naniwa 1K “Chocolate Bar” is one of the best economically priced 1K stones on the market. This stone holds its shape well, cuts rather quickly and leaves an edge that is refined enough for most tasks with a good amount of tooth. Like most other 1K stones, this stone also cleans up deeper factory scratches, makes transitioning from diamond plates and stones easier and cleaner, and is a good foundation stone before progressing to finer grits.

This stone is 1" x 4" in size mounted to an aluminum blank with a total thickness of 5-6mm and used with water only. It works best when soaked in water for a minute or two before use. Let air dry and store dry when not in use.

Abrasive Material: Aluminum Oxide

Ideal place in a sharpening progression:

• Ideal for harder steels and abrasion resistant steels.
• Starting grit for general repair and maintenance of an already sharpened but dull edge.
• After any diamond grit plate or stone to remove the deeper diamond scratches.
• After lower grit synthetic sharpening stones (120, 220, 320, 400, 600, 800 grit)
• After coarse belt grinder grits (80, 100, 120, 220, A65, A30 Trizact grit)
• Foundation for branching into natural stone progressions (JNats, Arkansas stones, BBW and Coticules, etc.)
• Before progressing to a higher grit medium grit stone or basic polishing stone (1,500 - 6K grit)

The Naniwa 1K Chocolate Bar is an economical sharpening stone that works on almost all types of knives, scissors, tools and chisels, including those made with abrasion resistant steels. While the 1x4 size is meant for use with the KME Sharpener, it is also a great size for a slip stone, field stone or a pocket stone for knife repairs and sharpening on the go.

This stone can also be used in a mix and match progression with other synthetic and natural sharpening stones as well as with other brands, such as Shapton, Sigma, Suehiro, Imanishi, Spyderco, King, etc. The Naniwa 1K Chocolate Bar is a Waterstone but can be used in conjunction with oil stones (such as Norton India and other carborundum and Arkansas stones) if the blade is wiped clean before and after switching stone types. 

On More Traditional Carbon Steel and Stainless Steel Edges the Chocolate Bar works on steels between RC 52 and RC 65 on the Rockwell C Hardness scale. The stone will make a very respectable and sturdy basic edge on steels like X50CrMoV15, AUS6, 440B, and most steels used by many kitchen knife makers like Henckels, Wüsthof, Gunter Wilhelm, F Dick, Victorinox, etc.

On the higher end of the hardness spectrum of traditional steel edges made with steels like 1095, 52100, 440C, Aogami White, Shirogami Blue, O1, W1, etc. The 1K Chocolate Bar really evens out the surface of these steels, leaving a consistent finish and very functional working sharp edge. The softer matrix of the stone is ideal for these harder steels.

On Carbide Forming Steel and More Abrasion Resistant Steel Edges such as VG-10, D2, M2, S35V, S90V, etc. The Chocolate Bar acts similarly to higher hardness carbon and stainless steels, prepping the surface to a consistent finish with a work sharp edge. 

Hacks and Tips:

• The general softness of this stone creates a paste very quickly that will finish the edge with a slightly higher grit than advertised.
• To add more aggression to this stone, create a slurry by rubbing the stone’s surface with a smaller 1K stone, or a coarse or extra coarse diamond plate and some water. The slurry will be milk chocolate in color.
• This stone is a little thirsty, so be sure to keep the surface wet with water when sharpening to avoid the black swarf from turning into a thick paste. This stone really likes a little paste on its surface to add a little horsepower and finer grit finish. Keep the stone wet enough with drops of water or a fine spray mist to allow the paste to be viscous, but not dry or too runny.
• Because of the softer matrix of this stone, this stone will require more frequent maintenance to keep it flat and even over time. Lap this stone with a coarse or extra coarse diamond plate, silicon carbide (SiC) powder, or low grit wet dry sand paper to keep it consistently flat and clean.

Comparable Stones: King 1K, Sigma 1K Oribest, Suehiro 1K R

Alternative Mid Level Stones: Naniwa 1K Goken Pro

Alternative Premium Level Stones: Jende 1K SF, Jende 1K SPK, Naniwa Chosera 1K, Sigma Select II 1K, Suehiro 1K Cerax