What Grit Whetstone Should I Use – How Many Sharpening Stones Do I Need?
You need at least three sharpening stones to keep you covered, a grinding stone, a sharpening stone, and a honing stone. If you have a bench or belt grinder, you can skip the first, coarse stone and get only two finer stones. One option is also to get a combination stone with sharpening and honing grits.
The grinding stone is coarse, 120-600 grit for fast repairing dull or chipped blade or re-shaping the blade bevel-angle, coarser the stone, the quicker the process. You can also shape some softer bladed tools with a fine mill file, e.g., axes, and hatchets. Sharpening stone, 1000-3000 grit, is for initial sharpening. This is a great sharpening stone for the money. Third stone is the honing stone, available from 4000 to 25000 grit, for final polishing and refinement of the edge. The finer the grit, the smoother and more polished/finished surface it does, and the sharper edge are possible.
A suitable sharpening grit progression is essential. Do not get stones with a too large gap between the grits, wide gap will slow your sharpening process down. With harder steels, you need to use smaller gaps. Softer, carbon steels can be sharpened with more significant gaps between grits.
The more whetstone grits you have, the slower your sharpening stones wear out and longer they stay flat. It is sensible to sharpen as little as possible on each consecutive grit. Remember, the flatter the stone, the better and sharper edge is possible!
Whetstone Stone Grit Chart
Here's a grit chart comparing various grit standards and the abrasive size in mm:
What is a Whetstone Stone Grit?
So, what do the whetstone grit numbers mean?
Sharpening stone grit is the number that defines the coarseness/size of the abrasive particles that are bound together to form a sharpening stone. It is printed usually on the side of the new sharpening stone.
The grit number is inversely related to the grain size. Grit number refers to the mesh size of the screen that is used to separate different sized abrasive particles. The smaller the number, the larger the abrasive particles, and the faster and more aggressively the stone cuts.
Conversely, the bigger the number, the finer the abrasive particles, and the finer the surface quality. On man-made whetstones, particle sizes are entirely consistent whereas natural stones don’t have inherent grit numbers.
How High/Fine Grit Should I Choose for Honing – Highest Sensible Grit Without Going for an Overkill
All types of sharpening stones are available from low to very high grits. What is the highest sensible grit for regular use and why such high grits are available?
Some types of blades should be sharper than others, it is a waste of time to hone certain cutting tools to high shine and extreme sharpness, some tools need a coarser edge to work correctly. There are basically two types of cuts you can make with cutting tools, a pushing cut and a slicing cut.
Woodworking and carving tools, razors, and axes/hatchets are tools that cut with a “pushing” cut. Their cutting edges need to be honed to high polish for them to work correctly and to produce a smooth surface. A well-honed, sharp edge is also more durable and longer lasting than a rough, sharp edge. Coarse bits tend to tear away from the edge easily blunting it faster.
Knives, scissors, and shears are “slicers” that work best when the edges are sharp but little rough.
Choice of the highest grit boils down to the intended use of the blade. Here are some pointers:
Best grit for sharpening kitchen knives
For kitchen knife sharpening, 4000-6000 grit is reasonable maximum, for many cuts in the kitchen, the microscopic serrated edge is useful when slicing meat and vegetable and sharpening with too high grit smooths the edge too much. Meat is cut best with a sharp but rough edge. Cooks use a tool called honing steel to maintain the knife edge, but it doesn’t sharpen the edge, but re-aligns and pulls the edge straight.
Best grit for sharpening razors
When sharpening razors, you need to go as high grit as possible. Some use even 30000 grit stones, like this, when finishing razor’s edge. A more sensible and cheaper alternative is to use a leather strop with a honing compound.
Best grit for sharpening chisels, plane irons/blades and woodcarving tools
Woodworking and woodcarving tools need to be sharp to reduce or prevent tear out. 6000-10000 grit is a reasonable maximum for plane irons/blades and chisels. The smoothing plane blade is the most demanding to sharpen; it needs to be sharpest of all the woodworking tools, 10000 grit is not overkill when sharpening smoothers. A well-honed edge stays sharp longer, and it is easier to maintain than coarse edge. For maintaining a sharp edge in woodcarving knives, chisels, and gouges use a leather strop with honing compound regularly.
Best grit for sharpening scissors and shears
Scissors and shears. For household scissors, quite coarse 240 grit is enough, fabric cutting shears should be polished with as high as 6000 grit for best performance.
Best grit for sharpening axes and hatchets
Axes and hatchets, max 600 grit for felling, splitting, and other all-purpose axes. Ax sharpening puck is handy for in-situ sharpening needs. Carvers hone their carving axes, adzes, and hatchets to a very high shine for best surface quality. For carving purposes, hone your ax to max 6000 grit.
Best grit for sharpening mower blades
I don’t recommend using whetstones when sharpening mower blades. Dull or chipped mover blades are best ground with mill file or grinder.
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