Chainsaw

Approximately 36,000 people are treated in emergency rooms for chainsaw injuries every year in the United States, with the average injury requiring 110 stitches. That statistic is not a reason to avoid chainsaws — it is a reason to understand them before picking one up. A chainsaw operated with proper personal protective equipment (PPE), correct technique, and a maintained chain is genuinely safe. An operator who skips chaps, ignores chain sharpness, and doesn't understand kickback is betting on luck.

The chainsaw earns its place in a self-reliance toolkit because it does work no other tool matches: clearing a downed tree from a road in minutes, processing a cord of firewood in an afternoon, managing forest property that would take weeks with a bow saw. The trade-off is fuel dependence, mechanical complexity, and a higher injury potential than any other hand tool on this page.

Choosing bar length and engine size

Bar length — the measurement of the cutting portion of the guide bar — determines what the saw can cut, not how powerful it is.

10 to 14 inches (25 to 36 cm): light pruning, small limbs, firewood from wood under 8 inches (20 cm) in diameter. Lightweight and maneuverable. Good for one-handed limbing work from a ladder.
16 to 20 inches (41 to 51 cm): the practical range for most property owners. Handles firewood processing, storm cleanup, and trees up to 18 inches (46 cm) in diameter efficiently. A 16-inch (41 cm) saw is the best general-purpose choice for most households.
24 inches (61 cm) and above: professional forestry and milling work. Heavier, more powerful engines, higher fuel consumption, and significantly harder to control for occasional users. Not recommended unless your property routinely requires felling large timber.

A basic rule: your bar should be at least 2 inches (5 cm) longer than the diameter of what you're cutting most often, so you can complete a cut in one pass. Cutting with repeated underpowered passes increases kickback risk and wastes time.

Engine size for gas models is measured in cubic centimeters (cc). A 30-40 cc engine paired with a 16-inch (41 cm) bar handles most homeowner tasks. A 50-60 cc engine is appropriate for 18 to 20-inch (46 to 51 cm) bars and sustained production work.

Battery-electric chainsaws have become genuinely capable for homeowner use. A 40V or 80V battery platform paired with a 16-inch (41 cm) bar handles storm cleanup and moderate firewood processing. They start instantly, require no fuel mixing, and produce no exhaust — significant advantages for garage use and urban property. Their limitations are battery runtime (typically 30 to 60 minutes of cutting per charge) and power under sustained load in large-diameter hardwood, where gas still holds an edge.

PPE — non-negotiable before starting

Chainsaw injuries follow a predictable anatomy: 40% occur to the legs, with the upper left thigh being the most common single injury site. The back of the left hand is the second most common. Both are directly protected by standard chainsaw PPE.

Chainsaw chaps or pants: These are the single most important piece of chainsaw PPE. Made with layers of cut-resistant Kevlar fibers, they jam the chain immediately on contact — stopping the saw before it reaches skin. Studies show that wearing chaps reduces chainsaw injuries by 75% or more. They are not optional for any chainsaw operation. OSHA requires them in occupational settings; treat that standard as the minimum for private use.

Helmet with face shield and integrated hearing protection: Chainsaws run at 100 to 120 decibels — sustained exposure above 90 decibels causes permanent hearing loss. A certified arborist helmet combines impact protection, a wire mesh face shield (which deflects chips without fogging), and ear muffs in one unit.

Cut-resistant gloves: Protect the left hand specifically — the hand that holds the front handle. Standard leather work gloves are inadequate. Look for gloves with Kevlar backs.

Steel-toed boots or chainsaw boots: Flying chips and a dropped saw both threaten your feet. At minimum, steel-toed work boots. Chainsaw boots with cut-resistant uppers are the correct tool for frequent operators.

Kickback is the primary cause of severe chainsaw injuries

Kickback occurs when the tip of the guide bar contacts an object or when the wood pinches the chain in the cut. The saw rotates upward and toward the operator in a fraction of a second — faster than you can react. Avoid contact between the bar tip and any surface. Never bore-cut without specific training. Keep the chain sharp — a dull chain in a pinching cut is a common kickback precursor. Engage the chain brake before repositioning.

Starting and basic technique

Pre-start checklist (every session): 1. Inspect the chain for sharpness, correct tension, and no damaged or missing teeth. A sharp chain cuts cleanly with minimal pressure; a dull chain produces sawdust instead of chips and requires you to push. 2. Check bar oil reservoir — the chain must be lubricated continuously during operation. An unlubricated chain overheats and can seize or snap. 3. Check fuel level and mixture (for gas saws). Standard ratio is 50:1 gasoline to two-stroke oil unless the manufacturer specifies otherwise. 4. Test the chain brake — push it forward with your wrist; it should stop chain movement immediately. 5. Verify all guards are in place.

Felling a standing tree: Plan your cut before starting the saw. Identify the natural lean direction, your escape route (diagonally back from the felling direction, not directly behind — falling limbs follow the tree, not your route), and any obstacles the tree will hit when down. Make the notch cut on the felling side: a top cut at 60 degrees to horizontal and a bottom cut meeting it, removing a wedge equal to one-quarter of the trunk diameter. Make the back cut on the opposite side, 1 to 2 inches (2.5 to 5 cm) above the bottom of the notch — this creates the hinge that controls fall direction.

Bucking a felled tree: Work from the uphill side when possible. Understand whether the log is sitting on a compression or tension surface — a log suspended at both ends with its belly sagging will pinch a saw cutting from above; cut from below first to relieve tension, then finish from the top.

Field note

After any storm, wait 24 to 48 hours before cutting downed trees if the trees are on or near fences, structures, or other trees. A pinned tree under tension can release explosive force when cut — sending a 200-pound (91 kg) log airborne. Let gravity and the situation settle before you begin. Two days of patience costs nothing.

Chain maintenance

Sharpening: A sharp chain is the single most important safety and efficiency variable in chainsaw operation. Dull chains require you to push the saw through the cut — the extra pressure destabilizes your stance and increases pinch risk. Sharpen after every 2 to 4 hours of cutting, or when the chain produces sawdust instead of chips.

Use a round file matched to your chain pitch: most homeowner chains use a 3/8-inch pitch and a 5/32-inch (4 mm) file. File at 30 to 35 degrees to the bar, tilted 10 degrees down from horizontal. Every other tooth. Check that you're maintaining consistent depth by filing the same number of strokes per tooth — 3 to 5 strokes on a moderately dull chain.

Depth gauges (rakers) — the small curved tabs in front of each cutter — must be filed down periodically as the cutters wear shorter. If depth gauges are too high, the chain skims the surface instead of cutting. Use a depth gauge tool and flat file to maintain the correct height (typically 0.025 inches / 0.6 mm above the cutter).

Chain tension: A correctly tensioned chain hangs snugly in the bar groove with no sag on the underside, but can be pulled away from the bar by hand roughly 1/4 inch (6 mm). Too loose and the chain derails; too tight and it binds and overheats. Check tension after the first 10 minutes of operation on a new chain — new chains stretch.

Bar maintenance: Flip the bar end-for-end at each chain change. This distributes wear evenly across both rails. Clean the groove and oil ports with a thin tool after each session; packed sawdust blocks lubrication.

Fuel and storage

Gas chainsaws require fresh fuel. Ethanol-blended gasoline absorbs moisture and deteriorates quickly, leaving gummy varnish deposits in the carburetor. Two-stroke fuel older than 30 days degrades noticeably; beyond 60 days it causes starting problems. Use premixed alkylate fuel for saws stored more than a few weeks, or add fuel stabilizer and run the saw at the end of each season until the carburetor is dry.

Store the saw with the chain brake engaged, bar cover installed, and no fuel in the tank if it will sit for more than 30 days.

Battery-electric saws store better than gas models: no fuel system to degrade, no carburetor to varnish. Store batteries at 50% charge in a cool, dry location. A fully discharged lithium battery left for months may be unrecoverable.

Chainsaw readiness checklist

Select bar length matched to your most common task: 16 inches (41 cm) handles most homeowner needs
Assemble full PPE before first use: chaps, helmet with face shield and hearing protection, cut-resistant gloves, steel-toed boots
Check chain tension, sharpness, and bar oil before every session
Verify chain brake function before starting
Plan tree felling — escape route, hinge, notch angle — before starting the saw
Sharpen chain after every 2-4 hours of use or when producing sawdust instead of chips
For gas saws: use fresh fuel, add stabilizer for storage, run dry if storing more than 30 days
Flip bar end-for-end at each chain replacement; clean groove and oil ports after each session

The chainsaw handles volume production work. For smaller jobs, branches under 4 inches (10 cm) in diameter, and situations where fuel is unavailable, an axe or hand saw takes over. In storm cleanup and debris removal, the chainsaw works alongside the come-along for moving what the saw has cut — a combination that handles most fallen-tree scenarios without heavy equipment.