In this article, I’m going to explain everything you need to know about felling wedges and why they are important in your chainsaw inventory of tools. The felling wedge might look like a simple tool of humble importance, but in actuality, it might be the difference between success and a terrible accident while felling a tree. Felling wedges are primarily thought of as being used during the felling process, but they are equally important when bucking logs to help keep the saw kerf open and prevent pinching a chainsaw’s bar. Also, splitting wedges should never be used as felling wedges. Let’s dive in!
First, let’s tackle some terminology. Felling is the act or process of cutting down a tree. A felling wedge refers to the object we are discussing in this article and its shape. Driving refers to the act of hitting a felling wedge with the flat part at the back of an axe or a sledgehammer. Hinge refers to the area of wood you leave connecting the stump to the tree’s trunk to aid in guiding the tree to the ground. Saw kerf means the amount of wood removed or cut by the chainsaw’s chain in a piece of wood. The phrase “pinch” means the chainsaw’s bar has become stuck between the wood being cut as the saw kerf begins to close due to compression wood forces. Also, you will hear most people refer to felling wedges as “wedges,” but for this article, I will use “felling wedges” as a descriptive term to discourage improvisation with homemade substitutes.
Today, felling wedges are made of high-impact plastic instead of steel. This is due to numerous safety concerns. When metal contacts metal, such as when a running chainsaw chain hits a metal felling wedge or an axe or sledgehammer strikes it, there is a risk of metal fragments flying off and injuring an eye. This is another reason safety glasses (currently ANSI Z87.1-rated or higher) are important. Plastic felling wedges, on the other hand, are safer because the saw chain can cut through them and they tend to deform rather than shatter dangerously. Keep in mind that safety glasses are still necessary, as pieces of plastic can break off during repeated impacts that cause mushrooming of the heel area. Some brands of plastic felling wedges are harder and more durable than others. When a felling wedge becomes heavily damaged or deeply cut by a chainsaw, it is time to replace it.
Felling wedges come in different surface textures: smooth, textured and barbed or spiked. Smooth is exactly as it sounds: slick. Textured is best described as a smooth-to-the-touch sandpaper-like texture that doesn’t make it slick but is often described as being a smooth felling wedge when purchasing. Barbed or spiked (depending on the manufacturer’s choice of wording) has a surface with rows of raised bumps to better aid in gripping.
Felling wedges come in various lengths and heel heights. Most tree fellers carry three sizes: 5.5-inch, 8-inch and 10- or 12-inch wedges. For most forest landowners working with trees less than 20 inches DBH, the 5.5-inch and 8-inch wedges are used most often. Larger field and yard trees require longer wedges. The 5.5-inch wedge is commonly used when bucking logs to prevent the chainsaw bar from being pinched. Most felling wedges have a 1-inch heel, which is the area struck with an axe or sledgehammer. The length and height of a felling wedge directly affect the mechanical advantage gained. Longer wedges have a more gradual taper, making them easier to drive into larger or heavier trees, especially when compensating for lean. As the wedge is driven in, it lifts one side of the hinge and helps guide the tree to fall in the desired direction.
Stacking felling wedges during felling is dangerous because wedges can slip or be completely forced out. It is generally recommended to avoid stacking and instead use a wedge with a taller heel, such as 1.5- or 2-inch, instead of the standard 1-inch heel. However, if stacking is unavoidable, a barbed or spiked wedge is preferred. Operators often encounter this situation because taller wedges are less commonly stocked and may need to be specially ordered. Regardless, operators should always be prepared with the proper tools before starting a job.
Experience will help operators determine which wedge to use. If a single wedge is not enough, assess the situation and determine whether another wedge can be inserted (hopefully beside the original), to try to apply just enough pressure to lift the tree’s weight off the original felling wedge. Then return to the original wedge position with another wedge better suited for the situation. Always be careful not to break the hinge wood. The hinge controls the direction of the fall. If the hinge breaks, control is lost and the tree will fall unpredictably based on gravity and existing conditions.
I hope this article helps you understand the importance of the humble plastic felling wedge and why you should have several in different sizes and heel heights in your tool kit when cutting wood. Know your limits, seek training such as Clemson Extension’s Chainsaw Operation Classes and know when it is best to hire a professional for tree felling.
Author
Stephen Pohlman, Cooperative Extension, Area Forestry and Wildlife Agent
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