The 1x4 Naniwa Chosera 5K Grit stone is the first real polishing stone of the Chosera series. This stone is best used after a medium grit (1K-4K) stone to really start bringing out hair shaving sharpness and shine, and to prepare the edge for higher polishing grits, but it can still be used for light touching up and routine maintenance on dull, but otherwise intact, edges. It leaves a mirror polished work sharp edge that is more than acceptable for almost any knife or tool.

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: Aluminum Oxide

Ideal place in a sharpening progression:

• Starting grit for light repair and maintenance of an already sharpened but dull edge.
• After medium grit sharpening stones (1K, 2K, 3K, 4K grit)
• After finer belt grinder grits (A16, A6 Trizact grit)
• Before progressing to polishing stones (6K - 16K grit)
• A final stone for mirror polished sharpness on many knives and tools.

The Naniwa Chosera 5K sharpening stone 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. Naniwa Choseras are Waterstones 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 5K Chosera stone works on steels between RC 52 and RC 65 on the Rockwell C Hardness scale. On softer end stainless steels used by many kitchen knife makers like Henckels, Wüsthof, Gunter Wilhelm, F Dick, Victorinox, etc. such as X50CrMoV15, AUS6, 440B, this 5K stone leaves a highly polished edge that is more suited to slicing. On these steel types, stone can maintain a serviceable edge, but does require a lower grit stone for any real damage or change in profile. Also, the structural characteristics of the steel may get close to reaching its upper limits at this grit.

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 Chosera 5K establishes a full on mirror finish with a slicing edge. It can be used to maintain the sharpness, but will require a coarser grit stone to do more serious repairs or profiling. These harder steel types thrive in this higher grit atmosphere, and 5K can be a versatile final grit, or just the beginning of the journey to finer stones and stropping.

On Carbide Forming Steel and More Abrasion Resistant Steel Edges such as VG-10, D2, M2, S35V, S90V, etc., The 5K Chosera stone is a pure polishing stone and requires a properly prepped edge from lower grits in order to bring out the maximum potential of the shine. The cutting edge off the 5K is more slicing, but the carbides still give the edge some stiffness and bite. The edge off this stone can be used as is, or to be further refined with stropping or finer grits stones.

Hacks and Tips:

• Use a moderate amount of water when sharpening with this stone to avoid the black swarf from turning into a thick paste. A cleaner surface will cut faster than a thicker pasted one.
• If using this stone as a final or polishing grit, keep the black swarf viscous and it will produce a slightly more refined edge.
• Lap this stone with a medium diamond plate, silicon carbide (SiC) powder, or 220-320 grit wet dry sand paper to keep it consistently flat and clean.

Comparable Stones: Shapton 5K, Suehiro Cerax 5K