Chainsaw Chain Sizes Explained: Pitch, Gauge & Drive Links (Simple Guide)
Buying a replacement chainsaw chain shouldn't be complicated. But when you see numbers like "3/8 .050 56DL" on the box, it's easy to feel lost.
Here's the thing — there are only three numbers you need to know to get the right chain. Once you understand what they mean, you'll never buy the wrong one again.
The Three Numbers That Matter
Every chainsaw chain is defined by three specs:
1. Pitch — the size of the chain links
2. Gauge — the thickness of the drive links
3. Drive links — the total number of links in the chain
Get all three right, and the chain fits. Get any one wrong, and it won't.
1. Pitch — What Size Are the Links?
Pitch is the distance between three consecutive rivets on the chain, divided by two. But you don't need to measure it yourself — it's almost always stamped on your bar or listed in your saw's manual.
Common Pitch Sizes in Australia
| Pitch | Common Name | Typical Saw Size | Examples |
|-------|-------------|-----------------|----------|
| 1/4" | Quarter inch | Small battery/pole saws | Stihl MSA series, small Makita |
| 3/8" Low Profile** | Three-eighths LP | Light-duty homeowner saws | Stihl MS 170/180, Husqvarna 120/130 |
0.325" Point three-two-five | Mid-range saws | Stihl MS 230/250, Husqvarna 435/440 |
3/8" Three-eighths (standard) | Farm and professional saws | Stihl MS 261/271/391, Husqvarna 455/460 |
0.404" | Point four-oh-four | Large professional saws | Stihl MS 661, Husqvarna 390/395 |
The most common pitch in Australia for farm use is 3/8". If you've got a mid-to-large Stihl or Husqvarna, there's a good chance it runs 3/8".
How to Find Your Pitch
Check your bar — look near the tip or near where the bar enters the saw body. You'll usually see numbers stamped or etched there.
Check your manual — the owner's manual lists the chain specs.
Look at the old chain— if you still have it, the pitch is often printed on the packaging or stamped into the drive links.
2. Gauge — How Thick Are the Drive Links?
Gauge is the thickness of the drive links — the bits that sit inside the bar groove. The chain gauge must match the bar groove width exactly. Too thick and it won't fit. Too thin and it'll wobble.
Common Gauge Sizes
Gauge | Metric | Common On
|-------|--------|-----------|
0.043"(1.1mm) Thin , Small battery saws, pole saws
0.050" (1.3mm) Standard | Most homeowner and farm saws
0.058" (1.5mm) Thick ,Professional and large saws
0.063"(1.6mm) Extra thick , Heavy-duty professional saws
How to Find Your Gauge
Stamped on the bar — usually right next to the pitch number
In the manual — listed alongside other chain specs
-Measure it — if you have a calliper, measure the drive link thickness
3. Drive Links — How Many Links in the Chain?
The number of drive links determines the overall length of the chain. This is directly related to your bar length, but it's not a simple conversion — different pitch and gauge combinations can have different drive link counts for the same bar length.
Common Drive Link Counts by Bar Length
| Bar Length | Typical Drive Links (3/8" .050") | Typical Drive Links (0.325" .050")
|-----------|--------------------------------|----------------------------------|
12" | 44–45 | 49–50
14" | 50–52 | 56
16" | 55–57 | 62–67
18" | 62–66 | 68–72
20" | 70–72 | 78–80
24" | 84
These are guides, not guarantees. The exact count depends on your specific bar and saw combination. The best way to confirm is to count the drive links on your old chain.
How to Count Drive Links
Drive links are the teeth on the bottom of the chain that sit inside the bar groove. They look like small fins. Lay the chain flat and count every single one — don't count the cutters (the sharp teeth on top) or the tie straps.
Quick Reference: How to Find Your Chain Size in 2 Minutes
Method 1: Read the bar
1. Look at your chainsaw bar
2. Find the stamped numbers (usually near the tip or base)
3. You'll see something like: `3/8 .050 72`
4. That's your pitch, gauge, and drive links
Method 2: Read the old chain
1. Look at the old chain packaging or the chain itself
2. Find the three specs
3. Match them when buying a replacement
Method 3: Tell us your saw model
1. Send us your saw make and model (e.g. "Stihl MS 271")
2. We'll tell you exactly what chain you need
Common Chain Sizes for Popular Australian Saws
Here's a quick cheat sheet for the most popular saws we see in Australia:
Stihl
| Saw Model | Bar Length | Pitch | Gauge | Drive Links |
|-----------|-----------|-------|-------|-------------|
| MS 170 | 16" | 3/8" LP | .050" | 55 |
| MS 180 | 16" | 3/8" LP | .050" | 55 |
| MS 250 | 18" | 3/8" | .050" | 66 |
| MS 271 | 20" | 3/8" | .050" | 72 |
| MS 291 | 20" | 3/8" | .050" | 72 |
| Farm Boss (MS 271) | 20" | 3/8" | .050" | 72 |
| MS 391 | 20" | 3/8" | .050" | 72 |
| MS 461 | 25" | 3/8" | .050" | 84 |
Husqvarna
| Saw Model | Bar Length | Pitch | Gauge | Drive Links |
|-----------|-----------|-------|-------|-------------|
| 120 Mark II | 16" | 3/8" LP | .050" | 56 |
| 435 | 16" | .325" | .050" | 66 |
| 440 | 18" | .325" | .050" | 72 |
| 445 | 18" | .325" | .050" | 72 |
| 450 Rancher | 20" | 3/8" | .050" | 72 |
| 455 Rancher | 20" | 3/8" | .050" | 72 |
| 460 Rancher | 24" | 3/8" | .050" | 84 |
[IMAGE: Selection of different chainsaw chains in various sizes laid out | Alt: "Different chainsaw chain sizes for Stihl and Husqvarna chainsaws"]
What Happens If You Get the Wrong Size?
Wrong pitch:** The chain won't sit properly on the sprocket. It either won't fit at all or will jump and be dangerous.
Wrong gauge: The chain won't fit in the bar groove (too thick) or will sit loose and wobble (too thin). Both are unsafe.
Wrong drive links: The chain will be too long (can't be tensioned properly) or too short (won't go around the bar).
Bottom line: all three specs must match. Don't guess.
Still Not Sure? Here's the Easiest Way
If you're looking at your saw and bar and the numbers have worn off, or you just want to be sure:
1. Take a photo of your bar (both sides) and your old chain
2. Send it to us — we can usually identify the right chain from a photo
That's what we're here for. No point buying the wrong chain and having to send it back.
Need a replacement chain? Browse our chainsaw chains and bars we stock all the common sizes for Stihl, Husqvarna, and Echo saws & more.
Not sure what fits? Call Aaron 0431 183 421or email us (farmandacreco@gmail.com) with your saw model, and we'll sort it out.
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