What is the most crucial information needed to buy the correct chainsaw chain? The most important details are the chain’s pitch, gauge, and the drive link count. Knowing these three measurements ensures you get a chain that fits your saw’s bar and performs optimally.
A chainsaw chain is a complex but essential part of your cutting tool. To keep your chainsaw running smoothly and safely, you need to ensure you’re using the right chain. Buying the wrong chain can lead to poor performance, damage to your chainsaw, or even dangerous kickback. This guide will walk you through how to measure your chainsaw chain accurately, ensuring you select the correct chain type for your needs. We’ll cover everything from deciphering the markings on your old chain to using simple tools to measure it yourself.
Image Source: www.parkerbrand.co.uk
Why Accurate Chain Sizing Matters
Getting the right chainsaw chain size is not just about a perfect fit; it’s about safety and efficiency.
- Safety: An incorrectly sized chain can be dangerous. If it’s too loose, it can derail from the bar, causing injury. If it’s too tight, it can cause excessive wear on the bar, chain, and even the engine.
- Performance: A chain with the correct pitch and gauge will cut more efficiently. It will glide smoothly through wood, allowing you to complete tasks faster and with less effort.
- Durability: Using the correct chain reduces stress on your chainsaw’s components, extending the life of the bar, drive sprocket, and the chain itself. A mismatched chain can quickly wear down these parts, leading to costly repairs.
- Kickback Prevention: Kickback is a sudden, violent upward and backward motion of the chainsaw. While many factors contribute to kickback, an incorrectly sized or damaged chain can increase the risk.
Deciphering Existing Chain Markings
Often, the easiest way to determine your chain size is to look for markings on the chain itself or on the chainsaw bar. Many manufacturers stamp this information directly onto the chain or bar.
Examining the Chain
Look closely at the drive links (the parts that sit in the groove of the guide bar). You might find numbers stamped onto them. These numbers typically correspond to the chain’s pitch and gauge.
- Pitch: This is the distance between rivets, measured in inches. Common pitches are .325″, 3/8″, and .404″.
- Gauge: This is the thickness of the drive link, also measured in inches. Common gauges are .050″, .058″, and .063″.
For example, you might see markings like “3/8 .050” or “.325 .063” stamped on a drive link.
Inspecting the Bar
The guide bar is another prime location for sizing information. Look at the end of the bar that attaches to the chainsaw body, or the tip of the bar. You should find markings indicating the pitch and gauge.
- The bar size is often indicated by the length of the guide bar, measured in inches. This is a separate measurement from the chain’s specifications.
If you find markings, cross-reference them with your chainsaw’s manual or the manufacturer’s website to confirm.
Measuring Your Chainsaw Chain
If you can’t find any markings, or if you want to double-check, you can measure your chain yourself. You’ll need a ruler or a tape measure. It’s best to use a metal ruler for greater accuracy.
Measuring the Pitch
Chain pitch is one of the most critical measurements. It’s the distance between any three rivets, divided by two. In simpler terms, it’s the distance from one drive link’s rivet to the next.
How to Measure Pitch:
- Lay the chain flat: Ensure the chain is stretched out as much as possible on a flat surface.
- Identify three consecutive rivets: Find three rivets that hold the chain links together.
- Measure the distance: Place your ruler at the center of the first rivet and measure to the center of the third rivet. This measurement will be for three pitches.
- Calculate the pitch: Divide the total measurement by two.
Example:
If the distance from the center of rivet 1 to the center of rivet 3 is 1.5 inches, then the pitch is 1.5 inches / 2 = 0.75 inches. This translates to a 3/4″ pitch. However, common chainsaw pitches are .325″, 3/8″, and .404″. If your measurement is closer to 0.65 inches for three pitches, then your pitch is approximately 0.325 inches. If it’s around 0.75 inches for three pitches, it’s 3/8″.
Table 1: Common Chain Pitches and Their Three-Rivet Measurements
| Chain Pitch | Measurement between 3 rivets (approx.) |
|---|---|
| .325″ | 5/8″ (0.625 inches) |
| 3/8″ | 3/4″ (0.75 inches) |
| .404″ | 13/16″ (0.8125 inches) |
Note: Always measure from the center of one rivet to the center of another for accurate pitch determination.
Measuring the Gauge
Chain gauge refers to the thickness of the drive links. These are the parts of the chain that fit into the groove of your guide bar.
How to Measure Gauge:
- Locate a drive link: Find one of the flat sections of a drive link that rides in the bar groove.
- Measure the thickness: Use your ruler or a caliper (for more precision) to measure the thickness of this drive link.
Common gauges are .050″ (1.3mm), .058″ (1.5mm), and .063″ (1.6mm).
Table 2: Common Chain Gauges and Their Approximate Millimeter Equivalents
| Chain Gauge (inches) | Chain Gauge (mm) |
|---|---|
| .043″ | 1.1mm |
| .050″ | 1.3mm |
| .058″ | 1.5mm |
| .063″ | 1.6mm |
Counting the Drive Links
The drive link count is simply the number of drive links on the chain. This determines the chain length needed for your specific guide bar.
How to Count Drive Links:
- Lay the chain flat: Spread out the chain.
- Count each drive link: Start with one drive link and count every single drive link until you have gone around the entire chain. Drive links are the pieces that have the small tabs sticking down, designed to engage with the sprocket and sit in the bar’s groove.
It’s important to count all of them. For instance, a common chain length might be 72 drive links for a 20-inch bar, but this can vary depending on the saw model and its gearing.
Relating Chain Size to Bar Size and Tooth Count
The chain you choose must be compatible not only with your chainsaw’s drive sprocket but also with the guide bar.
Bar Size and Chain Length
The bar size is the length of the guide bar itself, measured from the tip to where it attaches to the chainsaw. While the bar size determines the overall length of the guide bar, the drive link count is what dictates the actual chain length that will fit it.
For example, a 20-inch guide bar doesn’t necessarily mean it requires a 20-inch chain. The chain length is determined by the number of drive links that wrap around the bar and the drive sprocket. Always use the drive link count to find the correct chain length.
Tooth Count and Chain Type
The tooth count on your guide bar’s tip sprocket can influence the chain’s smoothness of operation, but it’s not a primary factor in determining the chain’s pitch or gauge. The drive sprocket on the chainsaw itself is more critical for ensuring the chain meshes correctly.
The chain type encompasses all these specifications: pitch, gauge, and drive link count. There are also different types of chains based on their cutting edges (cutters) and how they are designed to cut.
- Cutter Type: Chains have different cutter designs (e.g., full chisel, semi-chisel, chipper) that affect cutting speed and aggression. While not related to measuring size, it’s important for performance.
Using Tools for Precision Measurement
While a ruler is usually sufficient, for ultimate accuracy, a caliper is the best tool for measuring chain gauge.
Using a Caliper
A caliper provides a more precise measurement than a ruler, especially for the small dimensions of chain gauge.
- Set the caliper jaws: Open the jaws of the caliper.
- Place jaws on the drive link: Position the jaws to precisely grip the thickness of a drive link.
- Read the measurement: Tighten the caliper gently and read the measurement on the caliper’s scale. This will give you a very accurate gauge reading.
Common Pitfalls to Avoid
Even with careful measurement, mistakes can happen. Be aware of these common errors:
- Measuring from the wrong point: For pitch, always measure from the center of one rivet to the center of another. For gauge, measure the actual thickness of the drive link that sits in the bar.
- Confusing pitch with other measurements: Pitch is a measurement of distance, not thickness or length.
- Not counting all drive links: Missed drive links will result in a chain that is too short or too long.
- Assuming bar length equals chain length: The bar size is the physical length of the bar, while the drive link count defines the specific chain length.
- Ignoring manufacturer specifications: Always try to find the original specifications for your chainsaw model.
Frequently Asked Questions (FAQ)
Q1: What happens if I use the wrong chain pitch?
A: If you use a chain with the wrong chain pitch, it will not mesh properly with the drive sprocket on your chainsaw. This can cause the chain to skip, jam, or damage both the sprocket and the chain.
Q2: Can I use a chain with a different gauge than recommended?
A: It is strongly advised not to use a chain with a different chain gauge. If the gauge is too thick, the chain will not fit into the bar’s groove. If it’s too thin, the chain may be loose and unstable, leading to excessive wear and potential derailing. Always match the chain gauge to your bar’s specifications.
Q3: How do I know if my chain needs replacing?
A: Signs of a worn-out chain include dull cutters that require more force to cut, the chain not cutting straight, excessive chain stretching that requires frequent tensioning, and visible damage to the cutters or drive links.
Q4: My chainsaw bar has a number on it, what does it mean?
A: The number on your chainsaw bar usually indicates the bar size (length) and sometimes the required chain pitch and chain gauge. For example, “20-3/8 .050″ would mean a 20-inch bar, requiring a 3/8″ pitch chain with a .050” gauge.
Q5: Where can I find information about my specific chainsaw model’s chain requirements?
A: The best sources are your chainsaw’s owner’s manual, the manufacturer’s website, or a label on the chainsaw itself. If you can’t find it there, measuring the existing chain as described above is the most reliable method.
By carefully measuring your chainsaw chain’s pitch, gauge, and drive link count, you can ensure you select the correct chain type that is compatible with your bar size. This meticulous approach guarantees safe operation, efficient cutting, and the longevity of your chainsaw.