The Secrets of Tool Sharpening

By The Mother Earth News Editors
Published on July 1, 1981
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With this assortment of hand-held tool sharpening devices and a bit of patience you can put an excellent edge on a knife, but for other tools they're less practical. Pictured on the top row from L to R are a soft Arkansas stone, buck sharpening steel, Smith hard Arkansas stone, and a Gerber sharpening steel. Below in descending order are a sharpening steel for stainless, sharpening steel for high-carbon, and a ceramics stick.
With this assortment of hand-held tool sharpening devices and a bit of patience you can put an excellent edge on a knife, but for other tools they're less practical. Pictured on the top row from L to R are a soft Arkansas stone, buck sharpening steel, Smith hard Arkansas stone, and a Gerber sharpening steel. Below in descending order are a sharpening steel for stainless, sharpening steel for high-carbon, and a ceramics stick.
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MOTHER EARTH NEWS' tool experts have come to prefer a multi-angled taper like this one for most shop tools.
MOTHER EARTH NEWS' tool experts have come to prefer a multi-angled taper like this one for most shop tools.
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MOTHER EARTH NEWS homemade belt sander/sharpener.
MOTHER EARTH NEWS homemade belt sander/sharpener.
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The taper is filed onto a kitchen knife with a fine-toothed instrument (note hand guard on file). Only one stroke is made per side before turning the blade over.
The taper is filed onto a kitchen knife with a fine-toothed instrument (note hand guard on file). Only one stroke is made per side before turning the blade over.
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The taper is smoothed on the wood-backed portion of the belt.
The taper is smoothed on the wood-backed portion of the belt.
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Blue coloration—which shows where the edge has been ground—is applied with a felt-tip marker.
Blue coloration—which shows where the edge has been ground—is applied with a felt-tip marker.
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The edge is worked into the blade against the center of the belt, with a gloved finger beneath. When there's no reflection from the edge, it's sharp.
The edge is worked into the blade against the center of the belt, with a gloved finger beneath. When there's no reflection from the edge, it's sharp.
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A polished finish is achieved by stroking the already sharp blade against a ceramic stick.
A polished finish is achieved by stroking the already sharp blade against a ceramic stick.
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A screwdriver that has been hollow ground against the rounded form of a caster is able to grip a fastener much more securely.
A screwdriver that has been hollow ground against the rounded form of a caster is able to grip a fastener much more securely.

There are few experiences more frustrating than attempting to work with a dull tool, but keeping keen edges on the average household’s supply of bladed implements can be a very time-consuming task. Consequently, we’d like to pass on a few of the time-saving methods our workshop brigade uses to keep its (sizable!) stock of equipment well honed.

A Versatile Edge

After working with a variety of different edge designs, we’ve come to favor a multi-angled taper for most of the shop tools and heavy-duty knives, while we prefer a rounded version of the same edge for kitchen cutlery.

Of course, other blade configurations are well-suited to specific tasks. Hollow-ground knives, for example, will slice food more easily than will blades with our preferred edge, but the former grind’s loss of strength limits its usefulness for many purposes. In fact, we’re inclined to think that hollow-grinding has only three legitimate applications: on carving knives, on decorative knives (it does enhance the appearance of a blade), and on flathead screwdrivers (where the relief helps the tool reach deeper into a fastener’s slot).

The specific angle to which a tool is sharpened should be determined by the duties that the implement must perform.

Wood chisels, planes, and similar shop items need a medium angle (about 30°) to peel back layers of wood, for example, whereas cold chisels, axes, and other heavy-duty implements need blunt angles if they’re to resist chipping.

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