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Gardening Knives |
Edge Angle
Gardening Knives get used to do work, and the guidance provided below is based on that.
These are usually folding knives, typically made by Victorinox and sold by Swiss Army or Felco. They are also made by Tina in Europe.
These blades are typically sharpened on only one side as shown in the picture to the right. Thusly, guidelines shown below are for Bevel Angles (β).
If the knife is sharpened on two sides, the included angle (α) would be double the bevel angle (β).
The blade can usually be resharpened by re-honing it; re-grinding the blade is rarely needed. If re-grinding it is needed, start with a higher grit; it is easy to grind away too much metal. The Tormek SJ Japanese grindstone will probably work unless the edge is badly mangled.
The sharpened edges are denoted in the pictures below using red.
Society grows great when old men plant trees under whose shade they will never sit.
Anonymous
In Peter Thompson’s book, Creative Propagation, he noted:
... in unskilled hands, knives are not easily maintained in a continuously sharp state and are all too capable of inflicting serious cuts (to the gardener, not just the plant). They also have the disadvantage of being the number one, ace carrier of virus diseases from one plant to another ...
With these thoughts in mind, please note the guidelines below, and on the web page, General Tool Maintenance, as it regards gardening tools.
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General Guidelines |
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Blade Type |
β |
Notes |
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| Propagating & Pruning | 30° |
Propagating & Pruning Blade These are commonly used
The blade has an overall angle of 15°, but the cutting edge is less acute as denoted by the value of β to the left. |
| Grafting | 30° |
Grafting Blade These are commonly used
The blade has an overall angle of 15°, but the cutting edge is less acute as denoted by the value of β to the left. Key Note: Do not sharpen the part shown in blue in the picture to the right (the part which looks like a camel's hump). That is a bark lifter which is used in the grafting process. It should not be any sharper than it was when purchased. This part projects out from the knife’s blade when closed, and if sharpened, it will cut the user’s hand and the trousers pocket into which the knife is placed. |
Blades with a concave edge need special attention when sharpening to not mess up the curved edge.
The YouTube video by Dr. Vadim Kraichuk, Sharpening knives with concave curves, is worth reviewing if you have questions on the approach to use.
I've not found value in adding micro/secondary bevels to pocket knives which get used, especially knives with blades which fold into a handle. Thusly, it is not recommended here. That said, the honing steps may add a slight micro-bevel.
If the sharpener wants to add one, an additional 2° should be sufficient. (More notes are also available on a different web page for Micro / Secondary Bevels.)
The Knife Angle Setter jig is greatly useful if using the WM-45 Knife Jig to hold the blade.
I find that usage of calculators for setting specific angles to a high degree of accuracy is not critical. It is much more critical to resharpen often. If you choose to use a calculator to achieve a specific angle to a high degree of accuracy, there are a number of online calculators that can also be used for sharpening knives.
