1x4 Sigma 3K Select II
1x4 Sigma Stones for the KME Sharpener
The 1x4 Sigma Select II 3K Grit stone is an excellent stone for light touching up and routine maintenance on dull, but otherwise intact, edges. This stone cleans up scratches from lower grit waterstones and leaves a lightly mirrored polished edge that is more than acceptable as a working sharp edge for almost any knife or tool, and sets the stage for further refinement to polishing 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:
- Starting grit for light repair and maintenance of an already sharpened but dull edge.
- After lower grit sharpening stones (400, 600, 800, 1K, 2K grit)
- After finer belt grinder grits (A16, A6 Trizact grit)
- Before progressing to polishing stones (4K - 10K grit)
- A final stone for initial polished sharpness on many knives and tools.
The 3K Sigma Select II sharpening stone is a premium level 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, or to remove unwanted burrs.
On More Traditional Carbon Steel and Stainless Steel Edges, the 3K 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 3K stone leaves a lightly mirrored edge that is more suited to slicing.
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 3K removes earlier lower grit stone scratches and starts bringing out a mirror finish with an edge that leans more toward slicing. It can be used to maintain the sharpness, and set the stage for further refinement.
On Carbide Forming Steel and More Abrasion Resistant Steel Edges such as VG-10, D2, M2, S35V, S90V, etc., The Sigma Select II 3K stone begins to polish the edge, allowing the edge off to 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 coarse or medium diamond plate, silicon carbide (SiC) powder, or 180-220 grit wet dry sand paper to keep it consistently flat and clean.
Comparable Stones: Jende 3K Platinum, Naniwa Chosera 3K
Alternative Mid Range Stones: Jende 4K Frenchs, Naniwa 4K Finisher, Suehiro 3K Yellow