Pruning Shears / Secateurs

Angles are shown in the end views of the upper blade (red) and lower blade (blue).

   

The Tormek KJ-45 or SVM-45 knife jigs work well to hold this, though the KJ-45 is recommended due to its better ability to handle the blade's thickness.

General Guidelines
Angle Recom. Notes Recommended
Tormek Jigs
β1 20°

This angle is not terribly critical and probably does not need to be addressed. What I have observed is (generally):

β1 = β2 - 10°

If the original angle is different, consider matching that.


KJ-45
Using the bottom stop

SVM-45
Using the collar pivot jig
β2 30°

This angle can be as high as 35°, though that will make cutting the branch harder.

In knife terminology, this is the micro or secondary bevel. For pruning shears, this edge is much wider though : 2-3 mm (1/16" - 3/32") wide. If it gets too big, β1 can be re-ground to make this smaller.

If the original angle is different, consider matching that.

β3 85°

This angle (i.e., the lower (blue) blade) could be as low as 80°; however it is not terribly critical. What is important is that the angle is sharp and not rounded over, and that the blade is not corruded with tree sap nor rust.

If the original angle is different, consider matching that.

Notes & Comments

Information regarding Grindstones
Sharpening Notes for the Pruner's Edges
KJ-45 bottom stop

KJ-45 Jig Notes:. When using the KJ-45, use the bottom stop (this is shown in the picture to the right, and is indicated using a red arrow).

Using the bottom stop is necessary to achieve the sharpening angle for β2.


SVM-45 Jig Notes:. When using the SVM-45, the collar pivot jig designed by CB (shown below) works best.

The collars are needed to ensure the SVM-45's handle is held close to the pruning shear blade, and is necessary to achieve the sharpening angle for β2. It also helps with swinging the blade across the grindstone, sharpening it across the curved blade's edge.


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).


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.


If the tool was exposed to any diseased plants or soil which is infected with pests, give it a quick wash in diluted bleach (1 part bleach to 8 parts water), and then rinse with plain water. Be sure to dry afterwards, and apply a thin coat of camellia oil.


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.


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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.