Understanding Chainsaw Chain Letters: A Guide

what do the letters mean on a chainsaw chain

Chainsaw chains play a critical role in cutting performance and safety. The letters printed on chainsaw chains contain important information that helps determine compatibility and proper selection. In this article, we will explore what the letters on chainsaw chains mean and how to use them to choose the right replacement chain.

What do the letters mean on a chainsaw chain?

what do the letters mean on a chainsaw chain

The letters on a chainsaw chain provide details about the chain’s pitch, gauge, cutter type, sequence, and more. Understanding these markings is key to identifying the proper chain for your saw.

Pitch and Gauge

The pitch and gauge measurements are two of the most important factors in chainsaw chain selection.

Pitch refers to the spacing between the rivets that connect the drive links. This spacing determines the size of the teeth and helps match the chain to the sprocket and guide bar. Common pitches are 3/8″, .325″, and 1/4″. The pitch must match exactly for proper performance and safety.

Gauge specifies the thickness of the drive links and helps determine the chain’s strength and cutting capacity. Thinner gauges like .043″ and .050″ are good for lighter cutting, while thicker .058″ and .063″ gauges handle more demanding tasks. Like pitch, the gauge should precisely match the original chain.

Understanding Chainsaw Chain Letters: A Guide

Chain Identification Letters

Chainsaw chain manufacturers use identification letters to indicate the chain’s attributes. For example, “73” in the sequence “73LG” tells the pitch and gauge – 3/8″ pitch and .050″ gauge. The other letters provide details on cutter type, sequence, and other features.

Oregon uses a system like “73LGX” while Stihl uses sequences like “36RS” and Husqvarna “H37.” Each brand has its own lettering convention that must be decoded to match the proper replacement chain.

Cutter Type and Sequence

The cutter type – chipper, semi-chisel, or chisel – impacts cutting performance and longevity. Chipper chains quickly get sharp but also dull faster. Chisel chains stay sharp longer but are harder to sharpen. Semi-chisel chains provide a balance of sharpness and durability.

The sequence refers to how the cutters and tie straps are arranged around the chain. Standard sequence has cutters at every other link while skip sequence increases spacing between cutters. The sequence must match the original for proper sprocket engagement.

Chainsaw Chain Brands

The major chainsaw manufacturers each have their own branded chains with distinct identification lettering.

Oregon Chains

Oregon uses a sequence like “95VPX” to identify its chainsaw chains. The “95” indicates .325″ pitch and .058″ gauge. “V” represents a semi-chisel cutter, while “P” is for standard 50 gauge drive links. The “X” denotes shield cutters for added safety.

Stihl Chains

Stihl’s chain ID system uses two letters and two numbers. The letters indicate the cutter type and sequence – “R” for chisel and “S” for semi-chisel, “RSC” for chisel skip. The numbers show the pitch and gauge – “63” = 3/8″ and .063″. A Stihl RSC3 chain has 3/8″ chisel skip cutters with .063″ gauge.

Husqvarna Chains

Husqvarna identifies its chainsaw chains using an “H” followed by numbers for the pitch and gauge. An “H30″ chain has .325″ pitch and .050” gauge, while “H80″ is 3/8″ pitch and .063” gauge. The cutter type and sequence are not specified in the ID letters.

How to Determine the Size of a Replacement Chain?

When an old chainsaw chain needs replacing, use these steps to identify the correct replacement:

  • First, find the pitch, which is typically stamped into the drive links. Measure between three rivets and divide by two to get the pitch in inches.
  • Next, use calipers to measure the drive link thickness to determine the gauge
  • Finally, count the number of drive links required to make a full wrap around the bar.
  • With the pitch, gauge, and number of drive links, you can precisely match the replacement chain to the original. Trying to install the wrong size chain is dangerous and will damage the saw.


Chainsaw Chain Maintenance and Safety

Proper chain selection, maintenance, and use of safety features are essential for safe, effective chainsaw operation.

Proper Chain Selection

Choosing the right chain involves matching the pitch, gauge, sequence, and cutter type to your chainsaw model and typical cutting application. Heavier duty saws and hardwoods need wider gauge chisel or semi-chisel chains while lighter saws and softwoods can use narrower gauge chipper chains. Always consult your saw’s manual for the proper chain recommendations.

Chain Maintenance

Regular sharpening, depth gauge adjustment, and lubrication are key for maximum chain life and performance. Immediately replace excessively worn or damaged chains rather than try to repair them. Also, keep the saw’s bar rails and sprocket cleaned and lubricated.

Safety Features

Many modern chains incorporate safety enhancements such as guard links and ramped drive teeth to reduce kickback risk. Skip and semi-skip sequence chains also help by spacing out the cutters. Carbide-tipped chains stay sharp longer for reduced kickback. Inspect chains before each use and replace any with cracked, bent, or excessively worn components.


The letter markings on chainsaw chains contain much important information on compatibility, capabilities, and safety. Taking the time to decode the chain identification using the manufacturer’s terminology is essential to selecting the optimal replacement chain. Proper chain maintenance and use of modern safety features then helps ensure safe, efficient cutting. With this comprehensive guide, you now have the knowledge to get the most from your chainsaw chain.

Frequently Asked Questions

How do I find the letters on my chainsaw chain?

Look along the drive links for etched or stamped lettering containing the pitch, gauge, cutter type, and sequence information. This may be located near the left or right rivet of each link.

What is the difference between a chisel and a semi-chisel chain?

Chisel chains have a flat top grinding that stays sharp longer for ripping in dirty or frozen wood. Semi-chisel chains have a partially rounded cutter for faster sharpening and smooth cutting in cleaner wood.

How often should I replace my chainsaw chain?

Replace chainsaw chains at the first sign of damage or excessive wear. As a general rule, expect to replace the chain after 25-40 hours of use with proper sharpening and maintenance.

Can I use a different brand chain on my chainsaw?

While you don’t have to use the same brand, the replacement chain must precisely match the pitch, gauge, sequence, and drive link count of the original for safe performance. Stick to manufacturer recommended chains when possible.

How do I sharpen my chainsaw chain?

Use a round file of the proper size for your chain along with a file guide to ensure the correct filing angle. Firmly insert the file and make smooth, even strokes outward to maintain the top plate angle. Follow with a depth gauge tool to adjust depth gauges.

What is a low-vibration chain?

Low-vibration chains use a dampening mechanism between the cutters and tie straps to reduce vibration and operator fatigue. This allows extended comfortable use.

How do I measure the pitch and gauge of my chainsaw chain?

Use calipers to determine gauge by measuring drive link thickness. For pitch, count and divide the number of drive links over a measured bar section like 10 inches. This gives the chain’s pitch in inches. Match these measurements to the replacement chain.

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