What Is a Double-Taper Felling Wedge (Lift Angle)
A double-taper felling wedge is a wedge with sloping faces that is driven into a tree’s back-cut kerf to help lift the stem and keep the cut open. “Lift angle” describes the taper’s geometry, not a standard lifting rating. The right wedge must fit the kerf, stay clear of the chain, and suit the felling plan.
A wedge can look simple enough to explain itself. Then a manual says “double taper” or “lift angle,” and suddenly a small piece of plastic seems to need its own engineering degree. The useful idea is simpler: the taper turns each strike into a small increase in thickness inside the cut. That can help support the tree, but it cannot replace a sound felling plan or make an unsafe tree safe.
What a double-taper felling wedge is
A felling wedge is a purpose-made tool that enters the back cut behind the tree’s hinge. Its sloped surfaces become thicker as the wedge is driven in. “Double taper” refers to the wedge’s sloping geometry, but makers may use the term in different ways, so check the product drawing for the exact shape.
In use, the wedge helps keep the kerf, or saw cut, from closing on the guide bar. It can also add lift to the back of the tree and help it begin to move toward the intended fall direction. The hinge remains essential: it guides the tree’s movement, and a wedge does not replace it.
The term “felling wedge” is sometimes used broadly. This guide is about a wedge intended to be driven into a felling back cut, not a splitting wedge for chopping firewood. Use a wedge and striking tool suited to the task and follow the tool maker’s instructions.
I have found that the most useful explanation is not “this wedge has more power,” but “this wedge gains thickness as it travels.” That distinction helps avoid treating the wedge like a jack with a known load rating.
What “double taper” and “lift angle” mean
The lift angle describes the slope of a wedge face. It tells you how quickly the wedge grows thicker over its length. “Double taper” is not one universal design or angle; it can describe two tapered faces, and the exact arrangement depends on the maker’s design.
For one straight face, calculate its angle with:
Angle = arctan((thick-end thickness − thin-end thickness) ÷ taper length)
Use the same units for all measurements. For example, if a face rises from 5 mm to 25 mm over 150 mm, the change is 20 mm. The face angle is arctan(20 ÷ 150), or about 7.6 degrees.
A simple estimate of thickness gain is:
Thickness gain ≈ insertion distance × tan(face angle)
At 7.6 degrees, 50 mm of travel gives about 6.7 mm of thickness gain along that face. This is a geometry estimate, not a promise of tree lift. Wood can compress, the wedge may not contact evenly, and the kerf may not match the wedge’s shape. With two tapered faces, the wedge’s overall change in thickness depends on both faces and their directions.
| Term | Plain meaning | What it does not tell you |
|---|---|---|
| Face angle | How steep one sloping surface is | A safe load rating |
| Included angle | The angle between two faces in a cross-section | How much a tree will move |
| Double taper | A maker’s description of the wedge’s tapered shape | One standard design or angle |
| Lift per insertion | Approximate thickness gained as the wedge moves in | Guaranteed lift at the tree |
Check the maker’s specification or drawing when you need the exact angle. Do not assume two wedges marked “double taper” have the same geometry or performance.
Choosing a wedge for the cut
Choose a wedge by fit, available insertion depth, tree and cut conditions, and the lift needed for the planned operation. Do not choose it based on engine size or guide-bar length; those do not define wedge compatibility.
A wedge should enter the kerf freely and sit where the moving chain cannot reach it. If it is too thick for the cut, do not force it in. If it is too short or narrow for the situation, do not assume harder blows will solve the problem. The required wedge depends on the cut and the felling plan, not on a universal tree-size chart.
| Check | What to look for | Why it matters |
|---|---|---|
| Kerf width | Wedge enters without being forced | A tight fit can damage the cut or wedge |
| Insertion depth | There is room to place and drive it safely | The chain must remain clear |
| Wedge condition | No cracks, severe wear, or damaged striking area | A damaged wedge may fail under impact |
| Material and tool | Wedge maker approves the intended striking method | Some wedges and strikers are not suited to every impact tool |
| Hinge and tree condition | The hinge is retained and hazards are assessed | A wedge cannot correct a poor or unsafe felling plan |
Felling wedges are commonly made from materials such as plastic or other impact-resistant materials, but construction varies. Use only the product as directed. Never strike a wedge with the chainsaw, and never allow the chain to contact it.
Equipment Setup & Safety Prep
Before cutting, assess the tree and the work area, then confirm the felling direction and retreat route. A wedge is one part of the setup, not a substitute for personal protective equipment, hazard checks, a planned hinge, or a clear escape path.
Look for lean, crown weight, dead limbs, decay, wind, nearby targets, and any other hazards that could affect the fall. Set an exclusion zone and identify a retreat route before starting the saw. Follow applicable work rules and standards, including ANSI Z133 and, where applicable, OSHA 29 CFR 1910.266.
Check that the wedge is in good condition and that the striking tool is appropriate for it. Confirm that the wedge can be placed in the planned back-cut position without entering the chain’s path. Follow the chainsaw maker’s specifications for the bar, chain, fuel, and maintenance; wedge selection does not change those requirements.
If lean, decay, a damaged hinge, or another hazard makes the fall hard to predict, stop and seek a competent faller. A wedge cannot remove those hazards.
Field Felling Operation
The wedge is placed in the back-cut kerf, behind the intended hinge and clear of the chain. Drive it in controlled increments while watching the tree and cut. If the tree does not respond as expected, stop and reassess rather than relying on stronger strikes.
- Make the directional notch and back cut according to the felling plan, preserving the intended hinge.
- Place the wedge in the back-cut kerf where it cannot contact the chain. Use the orientation specified by the wedge maker.
- Keep control of the saw and make sure the chain is clear of the wedge before striking.
- Drive the wedge incrementally with an appropriate striking tool. Watch for tree movement, cracking, hinge changes, wedge movement, or the kerf closing.
- If the tree begins to commit, follow the planned procedure and retreat along the route you selected. Stay clear until the tree and limbs have settled.
Stop if you see splitting, unexpected movement, a compromised hinge, or other signs that the tree is behaving differently than planned. A split running up the trunk is called barber-chairing. A wedge does not prevent it. Do not continue as if extra wedge force will make the situation safe.
Field examples: choosing and using the wedge
These examples are practical scenarios, not recorded case studies or performance tests. They show how fit and geometry guide a decision. Actual tree behavior depends on the tree, cut, wedge, and site conditions.
A wedge will not enter the kerf. The kerf may be too narrow for that wedge or the wedge may be poorly positioned. Do not hammer it in by force. Reassess the cut and planned placement while keeping the chain clear; if safe placement is not possible, stop and reassess the felling plan.
The wedge enters, but the tree does not respond. The calculated thickness gain does not predict how much the tree will move. The hinge, tree lean, contact, and wood compression all affect the result. Stop and look for unexpected movement or cut problems. Do not simply strike harder.
The stem shows signs of splitting. This may point to dangerous stress or a failing hinge. A wedge does not make the tree stable or prevent barber-chairing. Stop, move to safety according to the plan, and have a qualified faller assess the tree or choose another method.
The key lesson is that the wedge helps with a prepared cut; it does not repair a poor cut or turn a hazardous tree into a routine one.
Wedge, Saw Maintenance & Sharpening
Keep the wedge in good condition and the saw maintained to its maker’s instructions. Wedge damage and chain damage can create risks, but neither tool should be modified to make an ill-fitting wedge work.
After use, inspect the wedge for cracks, chips, heavy wear, or damage around the striking area. Do not use one that is damaged, mushroomed, or brittle. Clean off debris and check the saw for damage if the chain has touched a wedge. A chain strike can harm the chain, bar, or wedge.
Sharpen and maintain the chain according to the chainsaw manufacturer’s directions. Keep the wedge separate from the chain and bar during transport. Refuel or service the saw only when it is stopped and safe to handle.
Storage & Seasonal Care
Store the wedge clean and dry, away from conditions that could damage its material. Before the next job, inspect it again rather than assuming it is ready because it looked fine after the last use.
Follow the maker’s care instructions, especially for wedges made from plastic or other materials that can be harmed by unsuitable storage or impact. Replace a wedge if it is cracked, badly worn, deformed, or otherwise outside the maker’s guidance. Do not reshape or repair it unless the manufacturer allows that work.
Conclusion and FAQ
A double-taper felling wedge uses sloping faces to gain thickness as it is driven into the back-cut kerf. Its lift angle describes that geometry, not a standard capacity or a guarantee of tree movement. Choose a wedge that fits, keep it clear of the chain, preserve the hinge, and stop if the tree behaves unexpectedly.
Is a double-taper wedge the same as a regular felling wedge?
Not always. “Double taper” describes a wedge’s geometry, but manufacturers may use the term for different shapes. Check the product drawing.
What is the lift angle of a felling wedge?
It is the angle of a sloping wedge face. It describes how quickly that face gains thickness as the wedge moves into the cut.
Does a larger lift angle always mean more lifting power?
No. It means a steeper geometric rise, but actual tree movement depends on contact, wood compression, wedge placement, and the cut.
How do I calculate a wedge’s face angle?
Use arctan of the thickness change divided by the taper length. Measure both in the same units, and use the maker’s drawing for the face dimensions.
How much lift does a wedge provide per inch?
There is no universal amount. A geometric estimate is insertion distance multiplied by the tangent of the face angle; real lift may differ.
Can I use any wedge that fits in the back cut?
No. It must suit the cut and planned placement, remain clear of the chain, and be used as its manufacturer directs.
Can the chainsaw chain touch the wedge?
No. Chain contact can damage the chain, bar, or wedge and may injure the operator. Place the wedge outside the chain’s path.
Will a felling wedge stop barber-chairing?
No. A wedge does not prevent a trunk split or make an unstable tree safe. Stop and get a qualified assessment if splitting or unexpected movement occurs.
Does wedge choice depend on chainsaw engine size?
No. Choose the wedge for the kerf, insertion depth, and felling plan. Follow the chainsaw maker’s separate bar, chain, fuel, and maintenance specifications.
Can I strike a wedge with a chainsaw?
No. Use an appropriate striking tool approved for the wedge. Do not strike a metal wedge with a chainsaw or use a damaged wedge.
(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)
