Garden Augers

You can bury a lot of troubles digging in the dirt.

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Sharpening the top side of the auger's leading edge is generally recommended as this enables the auger to dig quite well. This is the area denoted in the red box in the picture to the left.

There is one design of the auger's screw threads I've seen where the cutting edge seems to take a sharp turn towards the bottom. In this case, it is recommended to sharpen the opposite edge.

In either case, the leading edge must be the lowest part of the helical screw thread which wraps around the axis.


Most of these augers are fully painted. Changing the leading edge's angle will surely expose fresh metal. Thusly, the notes below on Ongoing Maintenance should be followed.


A 6" smooth cut machinist’s hand file is useful to carry in your gardening tools box. Use it to resharpen the shovel as needed throughout the tool's usage for the day.

General Guidelines
α Notes
45° If this is a hand-driven auger (vs. one driven by a drill), and it is only used in clean dirt, a 30° edge angle may be useful. Do note though that this can lead to easier damage to the edge if stones or other hard objects are encountered.

Notes & Comments

Shaping the edge

New garden augers often have an angle (α) of 90°. Therefore, initial shaping of the edge is to be expected.

A machinist’s hand file such as a 12-14" bastard file is often sufficient for this task.

If you use an angle grinder, consider using a 120 grit flap disc. A metal grinding wheel may be needed for large-scale shaping. In either case, be sure to not overheat the metal too much: it weakens the metal.


Sharpening the edge

Use a machinist’s hand file.

  1. Start with a 8-10" medium (or second) cut file.
  2. Finish with a 6" smooth cut file, then use this file to remove the burr.

Ongoing Maintenance

Be sure to remove all caked-on dirt. A wire brush or putty knife can be useful for this. A well-kept tool will last your lifetime, and will still be usable by your children (and maybe your grandkids).


Camellia Oil Spray Bottle

Sap can be removed using a solvent. Acetone works well, but be sure to wear protective clothing as this is not kind to your body, and be sure the area is well ventilated.

After using any solvent, be sure to apply a thin coat of camellia oil to the tool. I like the spray bottle of camellia oil sold by Tools for Working Wood.

Some advocate using boiled linseed oil (BLO), but BLO often has heavy metals or other bad chemicals added for drying agents, and these are not good for you to handle, nor would they be good for the plants on which you might use this tool.


Exposure to Diseased Plants or Soil

If the tool was exposed to any diseased plants or soil which is infected with pests, give it a quick wash with alcohol. Be sure to rinse with water and then dry afterwards. Finally, apply a thin coat of camellia oil.

The recommendation by some for using bleach or trisodium phosphate is not followed here. Those products can damage the metal in the tool.


Tools in Storage

Gardening tools often get stored for a while after sharpening, so it is recommended to oil the sharpened surface with camellia oil. (Indeed, all unpainted surfaces would benefit from this.)

Petroleum jelly is another option.


About this site
Remember : The goal of sharpening is to produce sharp tools, and these tools can injure you if mishandled. Safety measures should be followed to protect yourself and those in your shop. Be sure to read and follow all instructions from the manufacturer, and and utilize proper safety equipment. Never consume alcohol or anything that could impair your judgement before sharpening tools, or using sharp tools. Comments can be sent via eMail to me at SharpeningHandbook@Gmail.com.