A sharpened chainsaw chain should pull itself into the wood and throw firm chips. When it skates across a log, makes fine dust, or needs heavy downward pressure, the fresh filing job has not restored the cutting action. The teeth may feel sharp against a glove, yet their working angles may still be wrong.
The most common cause is high depth gauges, also called rakers. Filing shortens each cutter, but the raker in front of it stays at the same height. Once the gap becomes too small, the raker rides across the wood and keeps the sharp edge from taking a proper bite. Wrong file size, poor file position, uneven cutter lengths, and a backward chain can cause the same trouble.
Quick Diagnosis Chart
| What the Saw Does | Likely Cause | First Check |
|---|---|---|
| Slides across the log | Depth gauges are too high | Measure them with the matching gauge |
| Makes powder instead of chips | Cutting corners remain rounded | Look for shiny edges under bright light |
| Needs hard downward pressure | Wrong file size or file position | Check the chain’s filing chart |
| Pulls to the left or right | Cutters differ from side to side | Compare tooth length and angle |
| Moves but will not cut at all | Chain is fitted backward | Check cutter direction on top of the bar |
| Grabs and chatters | Depth gauges are too low | Stop cutting and inspect each raker |
| Smokes or becomes very hot | Low oil flow or excess tension | Check the oil tank, groove, and tension |
| Cuts well for part of each chain loop | Some cutters were missed | Mark one tooth and inspect the whole loop |
1. Check the Depth Gauges First
Every cutting tooth has a small raised section in front of it. This section is the depth gauge, raker, or drag. It controls how far the cutting edge sinks into the wood.
The cutter becomes shorter every time it is filed. The raker must also be lowered at set intervals. When it stays too high, it reaches the log first. The sharp tooth then passes over the surface without removing a full chip.
This fault can fool the eye. The cutter may look bright and sharp. It may even catch against a glove. Yet the chain will rub across the log like a sled on hard snow.
Place the depth-gauge plate made for your chain over the cutter. The raker will rise through the slot when it needs filing. Remove only the metal above the plate with a flat file.
Some gauges have separate positions for hard and soft wood. Follow the mark that suits the chain and cutting job. Do not guess the height with a ruler or fingertip.
After lowering the top, restore the rounded front edge of the raker. Do not change the measured height during this step.
2. Make Sure the Depth Gauges Are Not Too Low
Lower rakers do not always produce a better cut. A raker filed below its proper setting lets the cutter take an oversized bite.
The chain may grab the log, shake the handles, or feed in hard pulses. The bar can bounce inside the cut. Kickback force may also rise.
A raker that is slightly low cannot be filed higher again. The cutter must become shorter through later filing before the height gap returns to a suitable range.
Replace the chain when the rakers were removed far below the specified setting. Do not keep running a chain that grabs hard or makes the saw difficult to control.
3. Confirm the Round-File Diameter
Chainsaw chains do not all take the same round file. The required diameter depends on the cutter pattern and chain model.
A file that is too large sits high in the cutter. It removes metal near the top while leaving a blunt side angle. The tooth may look clean, but it cannot reach forward and slice the wood.
A file that is too small sits low in the gullet. It can create a thin hooked edge. That edge may cut hard for a brief period, then fold over or dull very quickly.
Read the chain code from the box, drive link, or dealer record. Match it to the file chart from the chain maker. Common diameters include 5/32 inch, 3/16 inch, 13/64 inch, and 7/32 inch, but those sizes are not interchangeable.
Replace a smooth or clogged file. A worn file slides across cutter steel without removing enough material. A fresh file should bite with each forward stroke.
4. Check the File Height
The file must sit at the right height inside the cutter. Part of the round file normally rises above the top plate. The exact amount depends on the chain.
Holding the file too high creates a blunt side plate. The chain feels dull in wood even when the top edge looks sharp.
Holding the file too low creates a hooked tooth. A hooked chain may grab, vibrate, or lose its edge quickly.
A matching file holder controls the file position far better than freehand guessing. Rest the holder across the top plate and depth gauge. Keep it steady through each forward stroke.
Push the file from the inside of the cutter toward the outside. Lift it slightly on the return. Dragging it backward can wear the file without helping the cutting edge.
5. Check the Top-Plate Filing Angle
The top plate has a filing direction that can often be seen as a small line stamped across the tooth. Many crosscut chains use an angle close to 30 degrees. Ripping chains may use a much shallower setting.
A crosscut chain filed almost straight across can rub through end grain instead of slicing it. A steep angle can create a thin edge that weakens quickly.
Check the filing mark on the tooth or the chart for the chain model. Use a guide that shows the angle while the file moves.
Keep the same body position while filing all teeth that face one way. Turn the saw or move to the other side before filing the opposite cutters. This helps keep both sides alike.
6. Look for a Shiny Line on the Cutting Edge
Dirt, stone, wire, concrete, and sand can flatten the chrome cutting corner. A few light strokes may polish the damage without removing it.
Clean the chain and inspect each cutter under a bright lamp. A rounded edge often catches the light as a silver line. A sharp edge appears crisp and does not flash back at you.
Find the worst sound cutter. File until the shiny section disappears and a clean corner remains. Then bring the other cutters close to the same length.
A chain that struck concrete may need heavy metal removal. A saw shop can grind it evenly, though replacement may cost less when the damage reaches far into the teeth.
7. Make Every Cutter Close to the Same Length
Left-hand and right-hand teeth must do equal work. Most people naturally push harder while filing one side. After several sessions, one row can become shorter or steeper than the other.
Uneven cutters make a saw drift through the log. The cut may curve left or right even when the guide bar is held straight.
Choose the shortest undamaged cutter as the master tooth. File longer cutters until they sit close to its length. A cutter-length gauge or small caliper can help.
Do not rely only on counting file strokes. One tooth may have more damage and need six strokes, while another needs two. Judge the finished edge, length, and angle.
8. Check for Missed Teeth
A chain loop can carry many cutters. It is easy to lose the starting point and skip several teeth.
Mark the first cutter with a paint pen, chalk, or permanent marker. File every other tooth until the marked one returns. Move to the opposite side and complete the cutters that face the other way.
A missed tooth can cause a pulsing cut. The chain bites for part of the loop, then glides or bumps when the dull section enters the wood.
Rotate the chain by hand after the saw has been shut down and disconnected from power. Wear gloves. Check every corner for stains, shiny edges, different angles, or untouched metal.
9. Check Whether the Chain Is Backward
A backward chain is common after the loop has been removed for filing. It can travel around the bar normally while doing almost no cutting.
Look at the top edge of the guide bar. The sharp points of the cutters must face forward toward the bar nose. The cutters along the lower bar rail face back toward the engine.
Remove the battery, unplug the saw, or disconnect the spark-plug boot before changing the chain. Release the chain brake as directed in the saw manual.
Remove the side cover, turn the loop around, and seat the drive links inside the bar groove. Hold the bar nose up while setting tension.
10. Check Chain Tension
A chain can be sharp and still cut poorly when it is too tight. Excess tension creates drag between the drive links and bar rails. The engine loses chain speed, the bar grows hot, and cutting becomes slow.
When the chain is cold, it should rest against the lower bar rail without hanging in a loop. You should still be able to pull it around the bar by hand while wearing gloves.
Loosen the bar nuts slightly. Hold the nose of the guide bar upward. Turn the tension screw in small steps, then secure the nuts while the nose remains raised.
A chain that hangs far below the bar is too loose. A chain that cannot move by hand is too tight. Check tension again after the first few cuts because a newly fitted chain may settle.
11. Check Bar Oil Flow
A dry chain loses speed and becomes hot. Heat can make a good sharpening job feel weak within minutes.
Fill the oil tank with bar-and-chain oil. Remove the guide bar and clean its oil holes. Clear packed dust from the bar groove and the oil outlet on the saw body.
Inspect the nose sprocket. It should turn without rough spots or grinding. Replace the bar when the nose wheel is frozen, the rails are cracked, or heavy blue heat marks cover the metal.
After reassembly, test oil flow through the method in the owner manual. Many saw makers direct the bar toward a pale board or stump for a brief run. A light line of oil should appear.
Stop cutting when the chain remains dry, smoke rises from the bar, or the rails become very hot.
12. Check the Guide-Bar Rails
A worn guide bar can make a sharp chain lean inside the cut. The saw may curve, bind, or rub one side of the kerf.
Remove the bar and place a straight edge across each rail. The rails should stand even. A burred rail edge can pinch the chain or make it sit at an angle.
Light burrs can be dressed with the method stated by the bar maker. Replace the bar when the groove is badly widened, the rails are thin, the nose is loose, or cracks appear.
Flip a reversible guide bar during routine care. This spreads wear between its upper and lower rails.
13. Check the Drive Sprocket
The drive sprocket pulls the chain around the bar. Deep grooves in its teeth can make a newly sharpened chain run roughly or lose speed under load.
Remove all power before taking off the side cover. Inspect the sprocket for broken teeth, deep wear marks, wobble, or metal dust.
A worn sprocket can damage a fresh chain. Replacing only the chain may bring poor cutting back after a short work period.
Clutch and sprocket service differs by saw. Many gas-saw clutches use a left-hand thread. Dealer repair is the safer route when special pullers or crankshaft holding methods are needed.
14. Check Chain, Bar, and Sprocket Compatibility
The chain pitch must match the sprocket. Its drive-link thickness must match the bar groove. Its drive-link count must match the bar length and mount.
A chain with drive links that are too thick can bind in the groove. A chain with the wrong pitch may sit badly on the sprocket teeth.
Read the numbers stamped near the guide-bar tail. Compare them with the chain package. Bar length by itself does not identify the right loop.
Do not grind drive links thinner or force a mismatched chain into the groove. Fit the chain made for the bar and sprocket.
15. Check for Grinder Heat Damage
A powered bench grinder removes steel quickly. Heavy pressure or a slow grinding pass can overheat the cutter.
Blue or dark purple color near the edge is a warning. The tooth may become brittle, hard to hand-file, or quick to chip.
Use light passes and let the grinding wheel do the work. Dress a glazed wheel. Set the tooth stop so each cutter finishes at a similar length.
Replace a chain with badly burned teeth, cracked chrome, loose rivets, or grinder marks that reach the tie straps.
Safe Check Order
- Shut down the saw and disconnect its power.
- Put on gloves and eye guards.
- Check that the cutters face forward on top of the bar.
- Inspect each working edge under bright light.
- Confirm the round-file diameter.
- Check file height and top-plate angle.
- Compare the left and right cutter lengths.
- Measure every depth gauge with the matching plate.
- Check chain tension and free movement.
- Clean the oil holes and bar groove.
- Inspect the guide bar and drive sprocket.
- Replace the chain when damage passes its wear marks.
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Frequently Asked Questions
Why is my chainsaw still dull after sharpening?
The file may not have removed all rounded metal from the cutting corners. High depth gauges can also stop sharp teeth from reaching the wood.
Why does the chain make dust after filing?
The cutters may still have shiny, rounded edges. The file may also be the wrong size or held at the wrong height. A healthy chain throws chips rather than powder.
Should I file the rakers every time?
Measure them with the plate made for the chain. They often need attention after several cutter-filing sessions. Heavy cutter repair may call for an earlier check.
Why must I push down after sharpening?
High rakers are the leading cause. A file held too high can also leave a blunt side angle that will not self-feed.
Why does the saw cut crooked after sharpening?
The cutters on one side may be shorter, sharper, or filed at a different angle. Worn guide-bar rails can also make the chain lean.
How can I tell whether the chain is backward?
The sharp cutter points on top of the bar must face toward the bar nose. A backward loop can move but will not cut wood normally.
What happens when the rakers are too low?
The cutters take too much wood per pass. The chain may grab, chatter, shake the saw, or produce stronger kickback.
When should I replace the chain?
Replace it when the teeth reach their wear marks, rivets become loose, links crack, drive links bend, or careful filing no longer restores normal cutting.
The Bottom Line
When a chainsaw will not cut after sharpening, check the depth gauges before filing the teeth again. High rakers can make sharp cutters slide across wood without taking a full chip.
Next, confirm the file diameter, file height, and top-plate angle. Remove every shiny spot from the cutting corners. Keep the left and right teeth close to the same length.
Check that the chain faces forward, moves freely, receives enough oil, and matches the bar and sprocket. Do not force the saw through wood. A properly set chain should feed itself and leave firm chips behind.