Chainsaw Chain Code Identification Chart: Reading the Stamp on Your Chain

Most chainsaw chains carry a code stamped directly onto the drive link that tells you the exact pitch and gauge — no calipers required. The system differs by brand: Stihl splits the code between the drive link and the cutter, Oregon uses a two-digit series number, Carlton uses a letter prefix, and Husqvarna uses "H" codes that often map back to Oregon's numbering.

Most reputable chainsaw chain manufacturers — including Stihl, Oregon, Carlton and Husqvarna — stamp a specific identification code directly onto the drive link (the bottom tooth that rides in the bar groove). These codes are the "DNA" of your chain: if you know how to read them, they tell you the exact pitch and gauge without you ever picking up a set of calipers.

At Alpine Chain Co. we know these codes can look like hieroglyphics. This guide breaks down the coding language of every major brand so you can confidently identify your chain and order the correct replacement. Once you've decoded it, our chainsaw chain cross reference chart maps every Stihl, Husqvarna and Oregon code straight to its Alpine equivalent.

How to Identify a Chainsaw Chain in Three Steps

1. Clean a drive link. Find the shark-fin-shaped link that sits inside the bar groove and wipe the oil and sawdust off it with a wire brush or a rag.

2. Find the stamped code. Look for a small stamped number or letter combination — e.g. "91", "21", "3", "73", or "K1L".

3. Decode it below. Match the code to your brand's system to read off the pitch and gauge, then confirm the length by counting drive links.

What Do the Numbers and Letters on a Chainsaw Chain Mean?

Every manufacturer uses its own shorthand, but they all encode the same three things: pitch (the chain's size class), gauge (the drive-link thickness), and cutter type (chisel, semi-chisel or low-profile). Some brands put it all in one code on the drive link; Stihl splits it between the drive link and the cutter. The tables below translate each brand's markings into plain pitch-and-gauge figures. If you'd rather measure the chain directly instead of decoding a stamp, see our how to measure a chainsaw chain guide — it also explains what each spec (including drive-link count, or "DL") actually means.

1. Stihl Chains (The "Two-Part" System)

Stihl is unique. They often split their identification between the cutter (which gives the pitch) and the drive link (which gives the gauge).

Step A — check the drive link (finds the gauge). Stihl stamps the last digit of the gauge measurement on the drive link:

• 1 = .043" (1.1mm)

• 3 = .050" (1.3mm) — most common

• 5 = .058" (1.5mm)

• 6 = .063" (1.6mm) — standard for Stihl Farm/Pro saws

Step B — check the cutter (finds the pitch). Look at the side of the cutting tooth:

• 6 (or P) = 3/8" LP (Picco)

• 2 = .325"

• 3 = 3/8" Standard

• 4 = .404"

Stihl also names its chain families in letters: PM/PMM/PMN = Picco Micro (3/8" LP semi-chisel), PS = Picco Super (3/8" LP full-chisel), RM = Rapid Micro (semi-chisel), RS = Rapid Super (full-chisel). So an "RM" is semi-chisel and an "RS" is full-chisel.

Example: a "3" on the drive link and a "2" on the cutter → .050" gauge, .325" pitch → you need a .325" .050" chain.

See our Alpine Chain Co. comparison charts.

2. Oregon Chains (The "Series" System)

Oregon stamps a code on the drive link that identifies the chain's series — which encodes both pitch and gauge. Reading the Oregon system:

• The leading digits identify the pitch-and-gauge series (e.g. 90 and 91 are 3/8" LP families; 20, 21 and 22 are .325" families; 72, 73 and 75 are 3/8" standard families).

• The letter suffix identifies the cutter and features: PX / DPX / BPX / VPX families are semi-chisel (Oregon's chamfer-chisel), while LPX / EXL families are full (square-ground) chisel.

The most common Oregon codes you'll find on a drive link:

Example: you see "73" on the link → 3/8" Standard, .058" gauge. A DPX suffix means semi-chisel; an LPX suffix means full-chisel.

See our Alpine Chain Co. comparison charts.

3. Carlton Chainsaw Chain Chart (The Letter-Prefix System)

Carlton (now part of the Oregon group) uses a letter-and-number system where the leading characters identify the pitch and profile, and later letters flag the gauge and features. The common Carlton families:

Within a Carlton code, an L generally denotes a chisel (square-corner) cutter and C a chamfer/semi-chisel cutter; the gauge is confirmed by the accompanying drive-link stamp or the bar. If your Carlton code isn't listed, match on pitch, gauge and cutter type using the tables above — or send us a photo and we'll identify it.

See our Alpine Chain Co. comparison charts.

4. Husqvarna Chains (The "H" System)

Husqvarna chains are made either by Oregon (historically) or in Husqvarna's own Swedish factory (the X-Cut range). They use "H", "C" or "S" codes, though the drive link often still bears the Oregon-style number.

See our Alpine Chain Co. comparison charts.

5. Alpine Chain Co. Codes (The Plain-English System)

We got tired of codes you need a decoder ring to read, so ours spells out the specification in the part number itself. Once you know the format, you never have to look anything up again.

Every Alpine code follows the same structure:

[PITCH][GAUGE] – [PROFILE] – [DRIVE LINKS]

So LT50-S-52 reads as: 3/8" LP pitch, .050" gauge, Semi-chisel, 52 drive links. That's the whole specification in eight characters — nothing to cross-reference.

Part 1 — The pitch prefix (two letters)

Part 2 — The gauge number (two digits)

This one's simple: the digits are the gauge.

• 43 = .043" (1.1mm)

• 50 = .050" (1.3mm)

• 58 = .058" (1.5mm)

• 63 = .063" (1.6mm)

Part 3 — The profile letter

• S = Semi-chisel — the rounded working corner we spec as standard for Australian hardwood, because it holds its edge through grit and files back sharp in the field.

• F = Full chisel — the square-cornered, faster-cutting profile, available on our bulk reels for operators cutting clean, green timber.

Part 4 — The drive-link count

The final number is simply how many drive links are in the loop — 52 means 52 drive links. If you see R100 instead, that's a 100ft bulk reel rather than a finished loop.

Worked examples:
LT43-S-50 → 3/8" LP, .043" gauge, semi-chisel, 50 drive links (a Stihl MS 170 on a 14" bar)
EN58-S-72 → .325", .058" gauge, semi-chisel, 72 drive links (a Husqvarna 455 Rancher on an 18" bar)
PF63-S-84 → 3/8", .063" gauge, semi-chisel, 84 drive links (a pro Stihl on a 24" bar)
EN50-F-R100 → .325", .050" gauge, full chisel, 100ft bulk reel

Every Alpine chain is semi-chisel by default, specified for the abrasive, dry conditions of Australian hardwood rather than the softer timber most imported chain is designed for. (More on why in our best chainsaw chain for Australian hardwood guide.)

The Next Step: Confirming the Length

Finding the code solves the pitch and gauge — but the stamp does not tell you the length. Even with a "73" stamp (3/8" .058"), you still need to know how many links are in your loop:

• Count the drive links manually — see how to measure a chainsaw chain for the method and what "DL" means.

• Read the bar stamp on the tail of your guide bar (near the oiler hole) — it often lists the drive-link count directly.

From Code to Chain — Find Your Match

Once you've decoded your chain, match it to an Alpine loop. Our chainsaw chain cross reference chart maps every Stihl, Oregon, Carlton and Husqvarna code to its Alpine equivalent. Or go straight to the finder: put your numbers into Search by Bar Stamp, or enter your saw in Search by Chainsaw. Browsing by machine instead? Start at our complete chainsaw chain size guide. Every chain is backed by our Guaranteed Fit promise.

Chainsaw Chain Identification — FAQ

How do you identify a chainsaw chain?

Clean a drive link, find the stamped code on it, and match that code to your brand's system to read off the pitch and gauge. Then count the drive links to confirm the length.

What do the numbers on a chainsaw chain mean?

The numbers and letters stamped on a chainsaw chain's drive link encode its pitch, gauge and cutter type. Each brand uses its own system: Oregon uses a series number plus a letter suffix, Stihl splits pitch and gauge between the cutter and drive link, and Carlton uses a letter-prefix code.

How do I read an Oregon chainsaw chain code?

Oregon's leading digits identify the pitch-and-gauge series (90/91 are 3/8-inch low profile; 20/21/22 are .325-inch; 72/73/75 are 3/8-inch standard) and the letter suffix identifies the cutter: PX, DPX and BPX families are semi-chisel, while LPX and EXL families are full chisel.

How do I read a Carlton chainsaw chain chart?

Carlton codes use a letter-and-number prefix: N1C is 3/8" LP semi-chisel, K1L and K2L are .325", A1LM and A1EP are 3/8", and B1C is .404". Within the code, L generally denotes a chisel cutter and C a chamfer or semi-chisel cutter.

How do I read an Alpine Chain Co. part number?

Alpine codes follow the format pitch-prefix, gauge, profile, drive links. LT50-S-52 means 3/8" LP pitch, .050" gauge, semi-chisel, 52 drive links. The prefixes are NN for 1/4", LT for 3/8" LP, EN for .325" and PF for 3/8" standard; S means semi-chisel and F means full chisel.

What do the letters RM and RS mean on a Stihl chain?

On a Stihl chain, RM (Rapid Micro) is a semi-chisel chain and RS (Rapid Super) is a full-chisel chain. The PM and PS families are the low-profile Picco equivalents.

Can I identify a chain without a code stamped on it?

Yes — if the stamp is worn or your chain doesn't carry one, measure the pitch, gauge and drive-link count directly instead. Our how to measure a chainsaw chain guide covers the method.