1x6 Sigma 13K Select II

The 1x6" Sigma Select II 13K Grit stone is the final polishing stone in the Sigma Select II series, bringing out the ultimate slicing and shaving edge. This stone is best used after an earlier polishing grit (5K-12K) stone to really bring out shaving sharpness and full mirror shine, and to prepare the edge for higher polishing and stropping.

1" x 6" x 5mm in size and mounted to a steel blank, the Sigma 13K is used with water only and works best when soaked in water for a minute or two before use. Store in a dry place in between use.

Abrasive: Aluminum Oxide

Ideal place in a sharpening progression:

• Starting grit for light touching up of an intact edge. Ideal for straight razors.
• After lower polishing grit sharpening stones (5K -12K grit)
• Before progressing to further polishing stones and strops (15K+, 1 micron - 0.025 micron strops)
• A final stone for full mirror polished sharpness on your knives and tools.

The 13K Sigma sharpening stone is a premium sharpening stone that works on almost all types of knives, scissors, tools and chisels, including those made with abrasion resistant steels. Even though the 1x6 size is meant for use with the Edge Pro, Hapstone and TSProf sharpeners, it is also a great size for a slip stone, field stone or a pocket stone for knife sharpening on the go, or to remove unwanted burrs. 

On More Traditional Carbon Steel and Stainless Steel Edges, the Sigma Select II 13K 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 13K stone leaves a highly polished slicing edge. 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 Sigma Select II 13K establishes a full on mirror finish with a smooth slicing edge. It can be used as a stand-alone stone to maintain the sharpness, but will require a coarser grit stone to do more serious repairs or profiling. The edges one these harder steel types thrive in this higher grit atmosphere, and the 13K is an ultimate final grit for most knives and tools, 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 Sigma Select II 13K stone is a pure polishing stone and requires an edge to prepped properly by lower grits in order to bring out the maximum potential of the shine. While the full mirror effect will depend on the progression before the 13K, the sharpness will continue to improve as the matrix steel is abraded. 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.
• At this grit, you shouldn’t need much sharpening time to enhance the shine from previous grit stones.
• Lap this stone with a medium diamond plate, silicon carbide (SiC) powder, or 220-400 grit wet dry sand paper to keep it consistently flat and clean.

Comparable Stones: Naniwa 12K Super Stone, Suehiro 15K Gokumyo