How chainsaws are made
The first chainsaws were surgical tools for cutting bone, long before anyone took one to a tree.
- stations
- 8
- things upstream
- 78
- raw sources
- 25
- steps from the ground
- 11
The short version
A gas chainsaw's engine sits in a crankcase of die-cast magnesium, light enough to hold at arm's length. Makers cast and machine the engine parts, mold a fiber-reinforced hood, grind a steel guide bar and rivet a loop of chromium-plated cutting teeth. A centrifugal clutch links engine to chain, and springs or rubber isolate the handles from the vibration.
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Die-cast the crankcase
Molten magnesium alloy is forced at high pressure into steel dies, making the two halves of the crankcase. The process holds tight dimensions and allows thin walls, which cuts weight.
AZ91 magnesium alloy
Goes in -
Cast the engine parts
Cylinders with cooling fins, pistons and other aluminum or magnesium parts are cast for a single-cylinder two-stroke engine. Some saws now use a magnesium piston.
30 to 120 cc
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Machine to tolerance
Castings are machined where the crankshaft, piston and cylinder must fit within tight tolerances. Magnesium cuts easily, which keeps this step fast.
Goes in -
Mold the orange hood
The cover that shields the cylinder and muffler is molded from fiber-reinforced plastic, strong yet light.
Goes in -
Make the guide bar
Wear-resistant alloy steel becomes a long bar with a rounded nose and a slot around its edge to guide the chain. Professional bars are solid steel with a replaceable nose, and consumer bars are laminated with a small nose sprocket to tame kickback.
40 to 90 cm long
Goes in -
Rivet the cutter links
Specialized machines punch side plates, drive links and teeth, then rivet them into a loop. Each tooth is a folded tab of chromium-plated steel with two beveled edges, and left and right teeth alternate.
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Build the powerhead
Crankshaft and piston go into the crankcase along with the carburetor, the oil pump that feeds the bar, and a centrifugal clutch with its sprocket drum. Springs or rubber mounts decouple the handles from the engine, much like a car's suspension.
Goes in -
Fit bar and test
The bar bolts on under the clutch cover, the chain is tensioned, and the saw runs. At idle the clutch stays open so the chain sits still, and it only grabs as engine speed climbs.
idle 2500 to 2700 rpm
Worth repeating
- Two Scottish doctors developed a chain saw for cutting bone in the late 18th century, and it stayed in surgery until a cheaper twisted-wire saw replaced it in 1894.
- A chain brake can stop a running chain within milliseconds after a kickback.
- STIHL's magnesium piston lets one of its saws run at 14,000 rpm.
Back to the ground
Follow every input upstream and chainsaw starts as these 25 raw sources.
Everything it is made of See it on the map
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Keep walking
Sources
- Chainsaw
- Made in-house (STIHL Annual Report 2020)
- How We Use Magnesium In STIHL Tools
- Self-made (STIHL Journal)
Cite this page: "How chainsaws are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/chainsaw