A recent visit to a woodcraft show resulted in me buying a tool the seller described as a kerfing plane. I had seen something similar before but didn’t really know anything about them, so naturally I decided to do a bit of research.
The information in this post has been gathered and rewritten from several sources (listed at the end of the article), and I’m grateful to those authors for the information they have shared.
The kerfing plane is a relatively modern addition to the hand-tool woodworker’s kit. It was popularised by Tom Fidgen in his book The Unplugged Woodshop. The tool is designed to create a controlled saw kerf around the edge of a board. This kerf then acts as a guide for a handsaw when resawing timber.
Sometimes referred to as a rebate saw, the kerfing plane cuts a shallow, straight kerf parallel to the edge of a board. It is not intended to cut all the way through the wood, but rather to establish an accurate path that the saw can follow during the final cut.
Why Use a Kerfing Plane?
Resawing timber by hand is a common task in many woodworking projects. It might involve splitting wide boards into thinner stock, preparing timber for box making, or even producing long planks for boatbuilding.
A common technique when resawing by hand is to start the cut from all four corners of the board, flipping the workpiece frequently to keep the saw on track. While this method works reasonably well, it is still possible for the saw to wander slightly. When the cuts meet in the middle of the board, this can sometimes produce the dreaded “X” pattern inside the timber—often leaving a small hump on one piece and a matching hollow on the other.
These errors are rarely serious enough to ruin a project, but they do mean extra time spent cleaning up the surfaces.
The kerfing plane helps avoid this problem by cutting a shallow kerf along all edges of the board before resawing begins. Because a saw naturally follows the path of least resistance, it will tend to track within this pre-cut groove. The result is a straighter and more predictable cut with far less wandering.
How a Kerfing Plane Works
A typical kerfing plane consists of:
- A small saw blade mounted in a wooden or metal body
- A fence that keeps the cut parallel to the edge of the board
- A depth stop that limits how deep the kerf is cut
The fence ensures the kerf is cut at a consistent distance from the edge of the workpiece. Some kerfing planes have a fixed fence, meaning the kerf is always cut at the same distance from the edge. Others have an adjustable fence, allowing the position of the kerf to be changed for different tasks.
The depth of the kerf can also be adjusted, usually up to about ½ inch (12–13 mm). This is deep enough to guide the saw accurately without removing more material than necessary.
Typical Uses
A kerfing plane is useful whenever a straight and accurate saw line is required. Typical uses include:
- Resawing boards into thinner stock
- Cutting the lid from a box
- Establishing a guide kerf before sawing
- Creating a drip cut or drip line on a window frame
- Any task where a straight, controlled saw cut is needed
Because the kerfing plane only establishes the guide, the final cut is completed with a handsaw.
My Kerfing Plane
The kerfing plane I purchased is nicely made from a single piece of timber. The sole measures 18 cm in length and 5 cm in width, giving it a comfortable size in the hand.
It has an adjustable fence mounted to the sole, allowing the distance from the blade to be set between 0 and 2.3 cm.
The blade itself is 14 cm long with 17 teeth, set alternately left and right. Interestingly, the blade appears to have been repurposed from a handsaw, with every second tooth removed from the original blade.
The blade can be adjusted to allow a maximum cutting depth of about 1.5 cm.
There is an owner’s stamp at each end of the plane, but unfortunately there is no maker’s mark, so its origin remains a mystery.
Once I had the fence adjusted so it was parallel with the blade, I found the plane very easy to use. It cuts a kerf approximately 2.5 mm wide. To use it effectively, you start with only a small amount of blade exposed and gradually increase the projection until the desired kerf depth is reached.
Final Thoughts
Although it is a simple tool, the kerfing plane can make a noticeable difference when resawing by hand. By establishing a guiding kerf around the perimeter of the board, it greatly reduces the chances of the saw drifting off line.
For woodworkers who prefer working with hand tools, the kerfing plane is a clever solution that improves accuracy, reduces clean-up time, and makes resawing a far more predictable process.
References
- Tom Fidgen, The Unplugged Woodshop, Popular Woodworking Books.
- Bob Easton, “Kerfing Plane.” https://www.bob-easton.com/blog/kerfing-plane/
- The Purpose and Usefulness of a Kerfing Plane, Journeyman’s Journel. https://journeymansjournel.wordpress.com/2024/02/10/the-purpose-and-usefulness-of-a-kerfing-plane/