Chainsaw Guide: Bar Length, Gas vs. Electric, Chain Types, and Safety

A chainsaw is the fastest way to cut through wood and also one of the most dangerous tools a homeowner can operate. The spinning chain moves at roughly 60 MPH and will cut through flesh and bone as easily as it cuts through oak. Choosing the right saw for your needs, maintaining it properly, and following safety fundamentals is not optional. This guide covers power source selection, bar sizing, chain types, maintenance schedules, and the safety practices that keep experienced chainsaw users injury-free year after year.

Gas vs. Electric vs. Battery

Gas chainsaws deliver the most power and run continuously as long as you have fuel. They handle the largest bar lengths (20 inches and above), cut the hardest wood species, and work far from any power source. A gas saw with a 50cc to 60cc engine and a 20-inch bar is the standard choice for regular firewood processing and medium tree felling. The tradeoffs are significant: weight (typically 10 to 14 pounds without bar and chain), noise (over 100 dB, requiring hearing protection), exhaust fumes that make indoor or enclosed-space use impossible, and ongoing engine maintenance including fuel mix, air filter cleaning, spark plug replacement, and carburetor tuning.

Battery chainsaws have closed the gap dramatically in recent years. A quality 56V or 80V battery saw with a 16 to 18-inch bar handles most homeowner tasks: storm cleanup, firewood processing, tree pruning, and small tree felling. They start instantly with no pull cord, produce no exhaust, and run significantly quieter than gas models. Battery life limits continuous cutting to roughly 30 to 60 minutes per charge depending on battery capacity and the hardness of the wood, which is more than enough for most residential work sessions. Brands like EGO, Greenworks, and Milwaukee offer models that rival mid-range gas saws on cutting speed.

Corded electric chainsaws are the lightest and cheapest option but limited by cord length and power output. They work for occasional pruning and small limbs near the house. For anything more demanding, such as felling trees, bucking firewood, or clearing storm damage, the cord is both a practical limitation and a safety hazard. The cord catches on branches, creates trip hazards in uneven terrain, and limits how far you can work from an outlet.

If you already own a battery platform (DeWalt 60V, Milwaukee M18 FUEL, EGO 56V, Makita 36V), buying a chainsaw on that platform means using batteries you already own. The saw costs less as a bare tool, your existing batteries and charger work immediately, and you avoid accumulating yet another incompatible battery system. For many homeowners, platform compatibility is the most practical factor in the decision.

Bar Length and Saw Sizing

Bar length determines the maximum diameter of wood you can cut in a single pass. A 14-inch bar cuts through logs up to about 12 inches in diameter. A 16 to 18-inch bar handles logs up to roughly 16 inches. A 20-inch bar is the standard for firewood processing and medium tree felling, handling logs up to about 18 inches in a single pass. Longer bars require more powerful engines or higher-voltage batteries to drive the chain effectively through heavy cuts.

The most common homeowner mistake is buying a bar that is too long. A 20-inch bar on a saw you struggle to control is more dangerous than a 16-inch bar that you handle confidently and precisely. You can cut logs larger than the bar by making cuts from both sides, rolling the log between passes. A shorter, lighter saw that you can maneuver with control is always safer than a longer one that exhausts your arms and dulls your concentration after 20 minutes.

For pruning and light limbing work, a 12 to 14-inch bar is ideal. The shorter bar is lighter and more maneuverable in the canopy. For general homeowner use including firewood, storm cleanup, and small to medium tree felling, a 16 to 18-inch bar covers the vast majority of tasks. For regular firewood processing of large-diameter hardwood rounds, a 20-inch bar saves meaningful time on bigger logs but only if the engine or battery can drive it without bogging down.

Match bar length to engine or battery power. An underpowered engine pulling a long chain bogs down in cuts, causes the chain to stall mid-cut, and increases the risk of kickback. Every chainsaw manufacturer publishes a bar-length range for each saw model that reflects what the motor can drive safely and effectively. Stay within that published range. Mounting an aftermarket bar longer than the manufacturer specifies is asking for trouble.

Chain Types and Maintenance

Full-chisel chain has square-cornered cutting teeth that produce the fastest cuts in clean wood. Professional loggers and arborists prefer full chisel for its cutting speed. The trade-off is that it dulls faster in dirty or sandy wood and is more aggressive, which means a higher kickback risk especially in hardwood. Semi-chisel chain has rounded cutting teeth that stay sharp longer in dirty conditions, resist dulling from occasional ground contact, and have a lower kickback tendency. For most homeowner use, semi-chisel is the safer, more practical choice.

Low-kickback (safety) chain has extra guard links between the cutting teeth that reduce the chance of kickback, the most dangerous chainsaw event. Most consumer-grade saws ship with safety chain installed from the factory. It cuts slightly slower than full-chisel chain but dramatically reduces the most common chainsaw injury mechanism. Keep the safety chain on unless you have professional training and a specific reason for switching. The small difference in cutting speed is not worth the safety trade-off for residential work.

Sharpen the chain regularly. A dull chain requires more downward pressure to cut, heats up the bar and chain, cuts crooked as teeth on one side wear faster than the other, and significantly increases kickback risk. A sharp chain pulls itself into the wood with minimal pressure from the operator. If you find yourself pushing the saw into the cut instead of guiding it, the chain is dull. A round file matched to the chain pitch (the file gauge is stamped on the chain packaging) resharpens each tooth in just a few strokes. Get in the habit of sharpening every tank of fuel for gas saws or every 30 minutes of active cutting for battery saws. Sharpen immediately after any contact with dirt, rock, or metal, as a single moment of ground contact dulls every tooth on the chain.

Chain tension affects both safety and cutting performance. A loose chain can derail from the bar during cutting, which is extremely dangerous. An overtight chain wears the bar rails prematurely, strains the drive sprocket, and puts unnecessary load on the engine or battery. The correct tension allows the chain to pull away from the bar about 1/4-inch at the midpoint and snap back into the groove when released. Check tension every time you refuel or swap a battery. Chains stretch as they warm up during cutting, so a chain that was correctly tensioned when cold may need a slight adjustment after the first few cuts.

Safety Equipment and Technique

Chainsaw chaps or pants are not optional for anyone operating a chainsaw. They contain layers of cut-resistant fibers (Kevlar or similar ballistic material) that jam the chain and stop it within fractions of a second if the spinning chain contacts your leg. Most chainsaw injuries strike the left leg, which is the forward leg during the standard cutting stance. Chaps rated to UL Standard 98 have prevented thousands of amputations and severe lacerations. A quality pair of chaps costs $60 to $120 and lasts for years of residential use. There is no rational argument against wearing them.

A chainsaw helmet with integrated face screen and hearing protection combines three essential pieces of personal protective equipment into a single unit. The face screen blocks wood chips and debris from your eyes and face. The earmuffs reduce 100+ dB chainsaw noise to safe levels, preventing cumulative hearing damage. The hard hat shell protects your head from falling branches, which are a leading cause of fatality during tree felling operations. Many chainsaw injuries and deaths are caused by falling limbs, not by the saw itself.

Kickback is the most dangerous event in chainsaw operation. It occurs when the upper portion of the bar tip contacts an object, whether that is a branch, the ground, or pinched wood. When the chain at the tip grabs, it throws the bar upward and backward toward the operator in a violent arc that takes less than half a second. The chain brake, the large lever positioned in front of the top handle, stops the chain in milliseconds when your wrist pushes forward against it during a kickback event. The chain brake is your last line of defense. Never disable, remove, or fail to maintain it. Test it before every cutting session.

Never cut above shoulder height. Overhead cutting removes your ability to control the saw if it kicks back, and a falling cut piece can knock the running saw into your face or body. For limbs above shoulder height, use a pole saw or hire a professional arborist. The risk-to-benefit ratio of overhead chainsaw work is never in your favor, regardless of your experience level. Similarly, never operate a chainsaw from a ladder. The combination of an unstable platform, a powerful cutting tool, and the potential for kickback creates conditions that even professionals avoid.

Storing and Seasonal Maintenance

For gas chainsaws, proper seasonal storage prevents the most common startup problems. Before storing the saw for more than 30 days, run the engine dry or add fuel stabilizer to the tank. Stale fuel mix gums up the carburetor and fuel lines, and is the number one reason gas chainsaws fail to start in spring. Remove the chain and bar, clean the bar groove of compacted sawdust and oil residue, and check the bar rails for wear or burrs.

For battery chainsaws, store the batteries at roughly 40 to 60 percent charge in a cool, dry location. Fully charged or fully depleted batteries degrade faster in storage. Remove the bar and chain for cleaning. Battery saws require less seasonal maintenance than gas models, which is one of their practical advantages.

Regardless of power source, check the chain oil reservoir before every use. The bar and chain require constant lubrication during cutting. Running a chainsaw without bar oil overheats the chain and bar, accelerates wear on both, and can weld the chain to the bar in extreme cases. Most saws have an automatic oiler. Make sure the oil port is clear and the reservoir is full before each cutting session.

Frequently Asked Questions

What Size Chainsaw Does a Homeowner Need?

A 16 to 18-inch bar with a battery or gas engine handles the vast majority of homeowner tasks, including pruning, storm cleanup, firewood, and small tree felling. Start with a 16-inch saw if you are new to chainsaws. You can cut logs larger than the bar by rolling them and cutting from multiple sides. A saw you can control confidently is always safer than a bigger one.

How Often Should I Sharpen a Chainsaw Chain?

Sharpen after every tank of fuel (gas) or every 30 minutes of cutting (battery). If the saw produces fine powder instead of chips, the chain is dull. If you have to push the saw into the cut instead of letting it pull itself in, the chain is dull. Sharpen immediately after hitting dirt, rock, or metal. A single contact with the ground dulls every tooth on the chain.

Is a Battery Chainsaw Powerful Enough for Real Work?

Modern 56V and 80V battery chainsaws with 16 to 18-inch bars handle most residential cutting as well as equivalent gas saws. They cut the same wood species at comparable speeds for 30 to 60 minutes per battery charge. They lack the unlimited run time of gas for all-day firewood sessions, but for typical homeowner use of a few hours of cutting per season, battery saws are more than adequate. Carrying a spare battery effectively doubles your cutting time per session.

Related Reading

• Tree Care Tools
• Safety Gear Guide
• Battery Platform Guide