Chainsaws have become an essential tool for homeowners, landscapers, and arborists alike. They are used for a variety of tasks, from felling trees to cutting firewood. One of the most important aspects of chainsaw maintenance is keeping the chain sharp and properly tensioned. In order to do this, it is important to know how to correctly measure the chain for your saw.
There are a few different ways to measure a chain for a chainsaw. The most common method is to use a tape measure or a chain gauge. A tape measure can be used to measure the overall length of the chain, while a chain gauge can be used to measure the pitch of the chain.
The pitch of the chain is the distance between the drive links. The pitch is important because it determines the size of the sprocket that the chain will fit on. Chainsaw chains come in a variety of pitches, so it is important to choose the correct pitch for your saw. If you are unsure of the correct pitch for your saw, consult your owner’s manual.
Measuring the Guide Bar: A Vital Dimension
Measuring the guide bar correctly is crucial for determining the appropriate chain length for a chainsaw. Here’s how to measure the guide bar in detail:
1. **Locate the Guide Bar Stud Holes:** Identify the stud holes on both ends of the guide bar. These holes receive the bolts that connect the bar to the chainsaw. They serve as the reference points for the measurement.
2. **Measure Between Stud Holes:** Use a measuring tape or ruler to measure the distance between the centers of the two stud holes. This measurement represents the length of the guide bar, which is typically expressed in inches. Record this length accurately.
| Example |
|---|
| A guide bar measured between stud holes is 18 inches long. |
3. **Consider the Drive Link Projection:** The drive link projection, or offset, refers to the amount of the chain that extends beyond the front of the guide bar. This projection varies depending on the type of drive link on the chain.
For semi-chisel chains, the typical drive link projection is 0.025 inches, while for full-chisel chains, it’s usually 0.050 inches. When determining the chain length, account for the drive link projection by adding the appropriate amount to the measured guide bar length.
Determining the Drive Link Count: The Key Factor
To accurately measure a chain for a chainsaw, determining the drive link count is crucial. It refers to the number of drive links that connect the cutter teeth along the chain’s length. This count directly impacts the chain’s pitch, which determines the size and spacing of the chain’s drive sprocket and guide bar. The drive link count also affects the cutting efficiency and power consumption of the chainsaw.
Manual Counting Method
To manually count the drive links, follow these steps:
- Lay the chain flat on a surface.
- Start counting from the first drive link that engages with the drive sprocket on the saw.
- Continue counting until you reach the last drive link that connects with the top of the guide bar.
- Record the total number of drive links counted.
Table of Common Drive Link Counts
For convenience, refer to the following table for the most common drive link counts used on chainsaws:
| Pitch | Drive Link Count |
|---|---|
| 1/4″ | 40, 42, 45, 48 |
| .325″ | 56, 60, 63, 66 |
| 3/8″ | 50, 52, 56, 58 |
| .404″ | 47, 51, 55, 59 |
Gauging the Thickness: A Precise Measurement
Measuring the thickness of a chainsaw chain is crucial to ensure proper fit and performance. Here’s a step-by-step guide on how to do it accurately:
1. Gather Measuring Tools:
You’ll need a caliper or micrometer with a range of at least 0-10 mm. Clean the tools thoroughly to prevent contamination.
2. Select a Chain Link:
Choose a link near the center of the chain to represent the average thickness. Make sure the link is not damaged or deformed.
3. Align the Caliper or Micrometer:
Hold the caliper or micrometer perpendicular to the chain. Ensure the jaws are fully seated on the outer drive links, avoiding the cutting teeth.
4. Measure the Thickness:
Squeeze the jaws together until they gently touch the drive links. Read the measurement on the caliper or micrometer display. Repeat the measurement on several links to get an average.
5. Calculate the Average Thickness:
Typically, chainsaw chain thickness is measured in fractions of an inch. To convert millimeters to fractions, use the following table:
| Millimeters | Fraction of an Inch |
|---|---|
| 1.3 | 0.050″ |
| 1.5 | 0.063″ |
| 1.6 | 0.063″ |
For example, if the micrometer reads 1.6 mm, the average chain thickness is 0.063″ (1/16″).
Matching Chain Specifications to Saw Requirements
When selecting a replacement chain for your chainsaw, it is crucial to ensure that the specifications of the chain match the requirements of your saw. By considering factors such as the pitch, gauge, length, and cutter type, you can ensure optimal performance and safety. Below is a detailed explanation of each specification and how it impacts the chain’s compatibility with your saw:
Pitch
The pitch refers to the distance between the drive links on the chain. It is measured in inches. The pitch of the chain must match the pitch of the sprocket on your chainsaw. A mismatch can cause premature wear, damage to the saw, or kickback. Common chain pitches include 0.325″, 0.375″, and 0.404″.
Gauge
The gauge refers to the thickness of the drive links on the chain. It is also measured in inches. The gauge of the chain must match the groove width of the guide bar on your chainsaw. If the gauge is too wide or too narrow, the chain will not fit properly or cut efficiently. Common chain gauges include 0.050″, 0.058″, and 0.063″.
Length
The length of the chain is measured in the number of drive links. It must be compatible with the length of the guide bar on your chainsaw. A chain that is too long will overhang the bar and can cause kickback, while a chain that is too short will not reach the tip of the bar and will cut inefficiently. The length of the chain is typically stamped on the side of the drive links.
Cutter Type
The cutter type refers to the shape and design of the cutting teeth on the chain. There are various cutter types available, each designed for specific cutting applications. Some common cutter types include chisel, semi-chisel, and skip tooth. The cutter type should be selected based on the type of wood being cut and the desired cutting speed.
Ensuring Proper Fit: A Critical Consideration
1. Measure the Saw Bar’s Length
The saw bar’s length is the distance from the tip of the bar to the center of the bar’s mounting hole. This measurement can typically be found stamped on the side of the saw bar itself. If you cannot find the measurement stamped on the bar, you can measure it yourself using a tape measure or ruler.
2. Count the Drive Links
The drive links are the teeth on the chain that engage with the sprocket on the saw bar. To count the drive links, start at one end of the chain and count every other link until you reach the other end. The total number of drive links will be the number of drive links in the chain.
3. Determine the Chain Pitch
The chain pitch is the distance between the centers of two consecutive drive links. To determine the chain pitch, measure the distance between the centers of two consecutive drive links and then divide that measurement by 2. The result will be the chain pitch.
4. Calculate the Correct Chain Length
The correct chain length is determined by the following formula:
Chain Length = (Saw Bar Length – 2 inches) * 2 + (Drive Links x 2)
Example: For a 16-inch saw bar with 72 drive links, the correct chain length would be: (16 – 2) * 2 + (72 * 2) = 150
5. Adjust the Chain Length
If the chain is too long, you will need to remove links to get it to the correct length. If the chain is too short, you will need to add links to the chain to get it to the correct length.
6. Reinstall the Chain
Once the chain is the correct length, reinstall the chain on the saw bar. Make sure the drive links are engaged with the sprocket on the saw bar. Tighten the chain tensioner to the recommended tension.
7. Check the Chain Tension
After the chain is installed, check the chain tension. The chain should be tight enough to prevent it from sagging, but not so tight that it binds on the saw bar. You can check the chain tension by pulling up on the chain in the middle of the bar. The chain should deflect 1/16 to 1/4 of an inch when you pull up on it.
| Chain Pitch | Chain Gauge | Number of Drive Links | Correct Chain Length |
|---|---|---|---|
| 3/8″ | .050″ | 72 | 150 |
| .325″ | .058″ | 76 | 158 |
| .404″ | .063″ | 80 | 166 |
Troubleshooting Common Measurement Issues: Solutions
9. The chain is too loose
A loose chain can be dangerous and inefficient. To tighten the chain, follow these steps:
- Loosen the chain tensioner bolt or knob.
- Slowly turn the chain tensioning screw clockwise until the chain is snug against the bar.
- Tighten the chain tensioner bolt or knob securely.
- Recheck the chain tension by pulling on it with your fingers. It should be tight enough to resist pulling, but not so tight that it binds against the bar.
| Chain too loose symptoms: | Chain too loose solutions: |
|---|---|
| Excessive vibration | Tighten the chain as described above. |
| Chain jumping off the bar | Tighten the chain as described above. |
| Bar overheating | Tighten the chain as described above. |
| Decreased cutting efficiency | Tighten the chain as described above. |
If you are still having problems with the chain being too loose, consult your chainsaw’s owner’s manual or a qualified mechanic.
How To Measure A Chain For A Chainsaw
There are two ways to measure a chainsaw chain: by its pitch, gauge, and length, or by the number of drive links it has. The pitch is the distance between any three consecutive rivets on the chain. The gauge is the thickness of the drive links. And the length is the total number of drive links in the chain.
To measure the pitch and gauge of a chainsaw chain, you will need a caliper or a ruler. To measure the pitch, place the caliper or ruler across three consecutive rivets and measure the distance between them. To measure the gauge, place the caliper or ruler across the widest part of a drive link and measure the thickness.
To measure the length of a chainsaw chain, you will need to count the number of drive links in the chain. To do this, simply count the number of links that have a drive tang.
People Also Ask
How do I know what size chain I need for my chainsaw?
To find the correct size chain for your chainsaw, you will need to know the pitch, gauge, and length of the chain. You can find this information in your chainsaw’s owner’s manual or on the chainsaw itself. Once you have this information, you can use a chain size calculator to find the correct size chain for your chainsaw.
What happens if I use the wrong size chain on my chainsaw?
Using the wrong size chain on your chainsaw can damage the chainsaw and the chain itself. If the chain is too long, it can bind in the bar and cause the chainsaw to kickback. If the chain is too short, it will not be able to cut properly and will quickly become dull.
How often should I replace my chainsaw chain?
The frequency with which you should replace your chainsaw chain will depend on how often you use the chainsaw and the type of wood you are cutting. A good rule of thumb is to replace the chain every 6-12 months, or more frequently if you are cutting hard or abrasive wood.
