Yard Tools
Chainsaw chain explained: pitch, gauge and drive links
A chain is specified by three numbers and no brand name. Get all three right and any chain fits; get one wrong and none of them do.
Affiliate disclosure: we earn a commission if you buy through our links, at no extra cost to you. It never changes which product we rank first — here is how we're funded.
We have not tested these units. Every spec on this page comes from the manufacturer's own documentation and is linked to it. Every computed figure is arithmetic you can redo. Prices are checked daily — last verified January 1, 1970. Here is exactly how we pick.
Buying a replacement chain is the moment most people discover that a chainsaw is specified in numbers rather than brands. There are three of them, they all have to match, and every one of them is published on the spec sheet if you know what you are reading.
The three numbers
| Number | What it describes | What it must match | Consequence of getting it wrong |
|---|---|---|---|
| Pitch | Spacing of the links along the chain | The drive sprocket and the bar nose sprocket | The chain will not engage the sprocket correctly |
| Gauge | Thickness of the drive link that rides in the bar groove | The bar groove width | Too thick and it will not seat; too thin and it wanders in the groove |
| Drive link count | How many drive links the loop contains | The bar length and the tensioner range | The chain is too long or too short to tension |
What our two saws publish
| Tool | Bar | Pitch | Gauge | Drive links |
|---|---|---|---|---|
| EGO CS1804 chainsaw | 18 in | 3/8 in | 0.050 in | 62 |
| EGO PSA1000 pole saw | 10 in | 3/8 in | 0.043 in | Not published |
From the EGO CS1804 and EGO PSA1000 product pages, checked 3 September 2026. The PSA1000 page publishes pitch and gauge but not a drive link count, which is exactly the sort of gap that sends people back to the shop with the wrong chain.
Notice what that table says about owning both tools: same brand, same battery platform, same pitch — and different gauges, so they do not share chains. Two EGO saws in the same shed need two different spare chains.
Why gauge is a performance decision, not just a fitment one
The 0.050 inch versus 0.043 inch split is not arbitrary. A thinner drive link goes with a narrower kerf — the slot the chain cuts — and a narrower kerf removes less material per pass. Less material removed means less work, which suits a tool with less power available at the end of a 38 inch pole.
That is an important honesty point. The two published cut counts are measured on different jobs, so they are not a clean comparison of chain gauges. What they do show is the real energy cost of each tool doing the work it is rated for.
#ad Check the EGO Power+ 18" Chain Saw CS1804 price on Amazon — how we're funded.
Why commodity dimensions are worth paying attention to
A 3/8 inch pitch, 0.050 inch gauge chain is one of the most common specifications in the category. That has a practical consequence: replacements are available from many makers, in many cutter styles, at many price points, and you are not tied to one manufacturer's spare part.
A 0.043 inch narrow-kerf chain is a less common size. It is not exotic, but the shelf in front of you will have fewer options, and that is a real ownership cost on a tool you expect to keep for a decade.
#ad Check the EGO Power+ 10" Pole Saw Attachment PSA1000 price on Amazon — how we're funded.
Buying a chain without a mistake
- Read the bar, not the internet. Most bars are stamped with the pitch and gauge on the body near the mount. That stamp beats any listing.
- Count the drive links if you are unsure. Take the old chain off, lay it flat and count the teeth on the underside. It is tedious and it is definitive.
- Check all three before you buy, every time. A chain with the right pitch and gauge and the wrong link count is still the wrong chain.
- Buy two. A dull chain in the middle of a job is the reason people force a cut, and forcing a cut is how saws and people get hurt.
- Keep the packaging. The three numbers are on it, and next spring you will not remember them.
What we cannot tell you
We are not going to publish a sharpening angle, a file size or a chain-life figure for these saws, because neither manufacturer page states any of them and the correct values are chain-specific. The chain packaging and the tool manual give you the manufacturer's own figures — use those, not a number from a site that has never held the chain.
What we can tell you is what the three published numbers mean, which two saws share a pitch but not a gauge, and why commodity dimensions are quietly one of the better reasons to prefer one saw over another.
The products discussed
Specs are the manufacturer's own and linked to the page they came from. Prices come from a live daily check; where we have no verified price we say so rather than print a stale one.
EGO Power+ 18" Chain Saw CS1804
EGO · EGO 56V ARC Lithium · Our score 8.8/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
300 published cuts through a 4x4 on one 280Wh pack, on an 18 in bar -- a work figure rather than a runtime figure.
Published specs
| Bar length | 18 in |
|---|---|
| Chain | 3/8 in pitch, 0.050 in gauge, 62 drive links |
| Motor speed | 11,000 RPM |
| Cuts per charge | Up to 300 cuts on a 4x4 (5.0Ah) |
| Battery (kit) | 56V 5.0Ah |
| Weight | 14.5 lb with battery |
Source: 18" Cordless Chain Saw (CS1804), egopowerplus.com
280Wh (56V x 5.0Ah) over 300 published cuts = about 0.93Wh per cut. A useful way to size a pack: 100 cuts of firewood needs roughly 93Wh, so a 2.5Ah pack covers it with margin.
What the numbers favor
- Publishes work done (300 cuts on a stated material) rather than a vague runtime
- Standard 3/8 in pitch, 0.050 in gauge chain -- replacements are commodity items
- 18 in bar on a consumer cordless saw
- Runs on the same 56V packs as the mower, blower and trimmer
What they don't
- 14.5 lb with the battery fitted is heavy for extended overhead work
- The 300-cut figure is on a 4x4; hardwood rounds will be a fraction of it
your cutting is limbs under 6 in. An 18 in bar is more saw than that needs, and a 10 in pole saw keeps you off the ladder.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
EGO Power+ 10" Pole Saw Attachment PSA1000
EGO · EGO 56V ARC Lithium · Our score 8.1/10
#ad No verified live price right now, so we show none rather than a stale one. How we're funded.
70 published cuts from a 140Wh pack at 4.17 lb -- the honest answer for limbs you should not be on a ladder for.
Published specs
| Bar length | 10 in |
|---|---|
| Max cut diameter | 10 in |
| Chain | 3/8 in pitch, 0.043 in gauge |
| Pole length | 38 in (plus power head) |
| Cuts per charge | Up to 70 (2.5Ah) |
| Weight | 4.17 lb |
| Lubrication | Automatic |
Source: 10" Pole Saw Attachment for Multi-Head System (PSA1000), egopowerplus.com
140Wh (56V x 2.5Ah) over 70 published cuts = about 2.0Wh per cut, roughly double the CS1804's 0.93Wh -- a narrow-kerf chain on a long pole works harder per cut than a saw you can lean on.
What the numbers favor
- 70 cuts per 2.5Ah pack, published
- 4.17 lb attachment weight, published
- Automatic bar lubrication rather than a manual oiler
- Takes EGO's EP7500 extension pole for more reach
What they don't
- Attachment only -- needs an EGO PH1400 or PH1420 power head
- 0.043 in narrow-kerf gauge chain, less common than the 0.050 in on the CS1804
you have one overhanging branch. Renting or hiring is cheaper than a power head plus an attachment for a single afternoon.
How it scores
Scores are our editorial weighting of the published specs above, not a test result. They are deliberately kept out of this page's structured data.
Where to buy the tools on this page
Every link below is an Amazon affiliate link. We show no price we have not verified today, so where there is no live figure the link says "check price" and takes you to the listing to read it there.
Best overall
EGO Power+ 18" Chain Saw CS1804
EGO · EGO 56V ARC Lithium
Best pole saw on-platform
EGO Power+ 10" Pole Saw Attachment PSA1000
EGO · EGO 56V ARC Lithium
#ad As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. How we're funded.
Common questions
What chain fits my chainsaw?
What is chainsaw chain pitch?
What is chainsaw chain gauge?
What are drive links?
Is a narrow-kerf chain better?
Can I fit a longer bar to my chainsaw?
Sources
Read next
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- Best cordless saw setup for cutting firewood
About 0.93 watt-hours per 4x4 cut, published. How to size a firewood setup from that.
- Best cordless pole saw
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- How to read a yard tool spec sheet (and what its silences mean)
Which figures are comparable, which are marketing, and what a missing spec tells you.