Stihl MS 170 Chain Size: What Chain Fits (Australia Guide)

The Stihl MS 170 is one of the most common small chainsaws in Australia, and "what chain fits it" is one of the questions we get asked most. The short answer: the MS 170 runs a 3/8" LP (low profile) chain in .043" (1.1 mm) gauge, 44 drive links on the 12 inch bar, or 55 drive links on the 16 inch bar. You'll find chains to suit in our chainsaw chains and bars range.

That's the answer most people came for. The rest of this guide covers what those numbers actually mean, how to double-check your own saw in under a minute, where the MS 171 and the "Mini Boss" name fit in, and whether a tungsten carbide chain is worth running on a saw this size.

MS 170 Chain Specs at a Glance

Here's the full spec table for the MS 170, straight up:

Bar length	Pitch	Gauge	Drive links	Chain type
12" (30 cm)	3/8" LP	.043" (1.1 mm)	44	Low profile
16" (40 cm)	3/8" LP	.043" (1.1 mm)	55	Low profile

Two things worth noticing. First, the pitch and gauge never change on the MS 170, every MS 170 runs 3/8" LP pitch and .043" (1.1 mm) gauge. Second, the only thing that changes with bar length is the drive link count. So the question isn't really "what chain does an MS 170 take", it's "how long is my bar".

In Australia, the 16 inch bar is by far the most common setup, which makes the 55 drive link chain the one most MS 170 owners need.

Got a different bar length on yours?

Bars get swapped over the years, especially on second-hand saws. If your bar isn't 12 or 16 inches, the pitch and gauge stay the same, 3/8" LP and .043" (1.1 mm), but the drive link count will be different. Don't guess it. Count the drive links on your old chain (we'll show you how below), or send us a photo of the bar and chain and we can usually work it out pretty quickly.

What Those Numbers Mean in Plain English

Chain sizing trips a lot of people up because there are three measurements, and all three have to match. Here's each one without the jargon.

Pitch: 3/8" LP

Pitch describes the size and spacing of the chain's links. The "LP" stands for low profile, a lighter chain with shorter cutters that takes a narrower bite out of the wood. It's the standard fit for small-engine saws like the 30 cc MS 170, because the saw doesn't have to work as hard to pull it through the cut. It also runs smoother and is less grabby than full-size chain, which is exactly what you want on a light saw.

Gauge: .043" (1.1 mm)

Gauge is the thickness of the drive links, the little tabs on the underside of the chain that sit down inside the groove of the bar. The MS 170's bar groove is 1.1 mm wide, so the chain's drive links need to be .043" (1.1 mm) thick to match. Stihl's small homeowner saws run this thin gauge; the bigger Stihl farm and pro saws run a much thicker .063" (1.6 mm) gauge. The two are not interchangeable, more on that in the mistakes section.

Drive links: 44 or 55

The drive link count is how chain length is actually measured. Chains aren't sized in inches, bars are. A "16 inch chain" is really a 3/8" LP .043" (1.1 mm) chain with 55 drive links. When you're ordering, the drive link count is the number that confirms the chain will actually go around your bar and sprocket.

If you want the full rundown on how these three measurements work across every saw and brand, our guide to chainsaw chain sizes, pitch, gauge and drive links explained goes deeper.

MS 170, MS 171, MS 180 and the "Mini Boss" Name

Stihl's small-saw naming causes nearly as much confusion as the chain specs do, so let's clear it up.

MS 171

The MS 171 is the updated version of the MS 170. With a 16 inch bar, it runs exactly the same chain as the 16 inch MS 170, 3/8" LP pitch, .043" (1.1 mm) gauge, 55 drive links. If you've upgraded from an MS 170 to an MS 171 with the same bar length, your spare chains carry over.

MS 180

The MS 180 is the slightly bigger brother, and it also runs 3/8" LP in .043" (1.1 mm) gauge, 50 drive links on its 14 inch bar, 55 drive links on a 16 inch bar. So a 16 inch MS 180 chain and a 16 inch MS 170 chain are the same chain, but the shorter-bar chains are not interchangeable between the two saws. We've got a full Stihl MS 180 chain size guide if that's the saw in your shed.

The "Mini Boss" badge

In Australia, Stihl puts the Mini Boss name on its small homeowner saws, and most saws people call a Mini Boss are MS 170s or MS 171s. But the badge is a marketing name, not a model number, so don't order a chain off the nickname alone. Find the model number printed on the saw body. If it says MS 170 or MS 171, the specs in this guide apply. If it shows a different model number, or it's too worn to read, sizes can vary, count your drive links or send us a photo rather than guessing.

For any other Stihl, the MS 250, the Farm Boss range, the pro saws, our complete Stihl chain size guide covers every common model in one chart.

Standard vs Tungsten Carbide on an MS 170

Once you know your size, you've got one more decision: standard steel chain or tungsten carbide tipped.

The fitment is identical, pitch, gauge and drive links don't change. The difference is the cutting teeth:

• Standard chain: cheaper to buy, sharpens with a normal round file, but dulls quickly in dry hardwood and the moment it touches dirt.
• Tungsten carbide tipped chain: carbide teeth hold their edge up to 10x longer than standard chain, and they shrug off dirty bark, dusty logs and the odd accidental ground clip that would kill a steel chain on the spot. The trade-off is they need diamond sharpening rather than a hand file.

For an MS 170 the case is pretty simple. This saw mostly lives on firewood duty and property clean-up, cutting dry, dirty Aussie hardwood, which is exactly the work that blunts standard chains fastest. A carbide chain means you stop sharpening every session and just keep cutting. If you only cut clean, green softwood occasionally, standard chain is fine and cheaper.

The full comparison is in our tungsten carbide vs standard chainsaw chain guide, and you can browse the GoldStrike tungsten carbide range to see what's available. If you don't spot your exact size, send through your specs and we'll point you in the right direction.

How to Double-Check Your Chain Size

Takes about a minute. Three ways, in order of ease:

1. Read the bar markings

Most guide bars have the pitch, gauge and drive link count stamped into the metal, usually down near where the bar bolts onto the saw (sometimes near the tip). If yours are still readable, that's your answer, done.

2. Count the drive links

If the markings are worn off, count the drive links on your old chain. They're the tabs on the underside of the chain that ride in the bar groove. Lay the chain flat or loop it over your hand, mark your starting link with chalk or a texta, and count every tab the whole way around. On an MS 170: 44 means you've got the 12 inch chain, 55 means the 16 inch. If you land on a number that's miles off either, the saw may not be wearing its original bar, send us a photo and we'll sort it.

3. Check the model number

Find the model number on the saw body and match it against the table above, or against the complete Stihl guide if it's not an MS 170/171.

Common Mistakes to Avoid

These are the ones that catch people out, and they all end with a chain that won't fit or won't cut straight.

Mixing up .043" (1.1 mm) and .050" (1.3 mm) gauge

Both gauges are common in 3/8" LP chains, and the packaging can look near identical. A .050" (1.3 mm) chain is too thick to seat in the MS 170's 1.1 mm bar groove, and a .043" (1.1 mm) chain in a wider groove flops sideways and cuts crooked. Always match the gauge, not just the pitch.

Buying by bar length alone

"A 16 inch chain" is not one chain, different brands run different pitch and gauge combinations on the same bar length. Our 16 inch chain size guide for every brand shows just how many different chains share that label.

Borrowing specs from a bigger Stihl

Stihl's farm and pro saws run full 3/8" pitch chain in .063" (1.6 mm) gauge. That's a completely different chain to the MS 170's 3/8" LP .043" (1.1 mm), even though both get called "3/8 Stihl chain". A chain off the family Farm Boss will not go onto an MS 170.

Confusing 3/8" LP with full 3/8"

Same pitch number, different chain families. Low profile chain has smaller cutters and pairs with thin-gauge bars on small saws; full 3/8" is the bigger-saw chain. They're not interchangeable.

Still not sure? Our guide on how to choose the right chainsaw chain for your saw walks through the whole decision from scratch.

FAQ

What size chain does a Stihl MS 170 take?

3/8" LP pitch, .043" (1.1 mm) gauge, 44 drive links with the 12 inch bar, 55 drive links with the 16 inch bar. Most MS 170s in Australia run the 16 inch bar, so the 55 drive link chain is the common one.

Are Stihl MS 170 and MS 180 chains interchangeable?

On 16 inch bars, yes, both saws run the same 3/8" LP, .043" (1.1 mm), 55 drive link chain. On shorter bars they're not: the 14 inch MS 180 chain has 50 drive links and the 12 inch MS 170 chain has 44, so neither swaps onto the other.

What does "3/8 LP" mean?

LP stands for low profile. It's a lighter version of 3/8" pitch chain with shorter cutters and a narrower cut, designed for smaller, lower-powered saws like the MS 170. It is not the same chain as full 3/8" pitch.

Can I run a tungsten carbide chain on an MS 170?

Yes. Tungsten carbide tipped chains come in the same fitment, 3/8" LP, .043" (1.1 mm), with carbide cutting teeth that last up to 10x longer than standard chain. They're well suited to dry hardwood and dirty firewood work.

How many drive links does an MS 170 chain have?

44 on the 12 inch bar, 55 on the 16 inch bar. If your bar's been swapped at some point, count the drive links on your old chain to confirm before ordering.

TL;DR: Quick Reference

• Stihl MS 170 chain: 3/8" LP pitch, .043" (1.1 mm) gauge
• 12 inch bar = 44 drive links · 16 inch bar = 55 drive links
• MS 171 with a 16 inch bar takes the same 55 drive link chain
• Same chain as a 16 inch MS 180, but NOT the same as the bigger Stihl farm saws (.063" / 1.6 mm gauge)
• Never mix .043" (1.1 mm) and .050" (1.3 mm) gauge, the chain won't sit right
• Tungsten carbide version: same fitment, edge life up to 10x longer

Not sure which one fits? Send us your saw model, the numbers off your bar, or just a photo, call 0431 183 421 or email farmandacreco@gmail.com and we'll point you in the right direction. Otherwise, jump straight into our chainsaw chains and bars collection, we stock the common MS 170 sizes in standard and tungsten carbide.