Being a chainsaw user, you must have seen some numbers stamped on your saw. These numbers are extremely important when you need to replace the chain of your chainsaw.
Many people do not pay attention to these numbers because neither they are much highlighted, nor they are very much visible on every saw. However, they play a key role when finding a chain that’s compatible with your current saw. And so, understanding the chainsaw chain numbers is very important.
When your chainsaw chains get dull (which could be a risky situation if you keep using the dull chainsaw), you’ll definitely need to change the chain. And for that, your saw would require a chain that could either be from the same brand as your saw or some different brand.
No matter what brand you choose to buy a chainsaw chain, you’ll have to consider the chain blade numbers on your current chainsaw chain. This would help you buy a chain that’s exactly the size of your chainsaw and would fit perfectly.
Our article contains a detailed discussion on chainsaw chains with numbers on them, and what they actually mean and indicate. Continue reading if you’re interested to know the purpose of numbers on a chainsaw chain.
What Do the Numbers on a Chainsaw Chain Mean?
You might not notice this when you’ve newly purchased a chainsaw, but with the passage of time, you’ll know that there are certain numbers on a chainsaw chain. And to build an understanding of what they really mean is somewhat important.
The numbers on a chainsaw chain are an ID code that indicates the pitch and gauge measurements of the chainsaw chain. For a chain to be compatible with any chainsaw, it’s important to know the pitch and gauge of the chain. If these measurements match, you can have your chainsaw chain replaced with that one.
So, basically, Pitch and Gauge are the two most necessary measures mentioned on the saw that you’ll see while observing the numbers on a chainsaw chain. Remember, every chainsaw chain has a number on it, and it indicates pitch and gauge measurements of the chain.
Consider that you have a number S20 45 70W on your chainsaw chain. To know what it means, here’s how you’ll read it.
- Starting from the left-most, the letter ‘S’ indicates the manufacturing brand which in this case is ‘Stihl’. The number 20 with S just shows the length of the bar. This means, the chainsaw in front of you is from Stihl and has a bar length of 20 inches.
- 45 means that the bar has a gauge measurement of 0.045 gauge.
- Next, 70 is the Drive link measurement which tells the number of drive links in your chainsaw chain that run on this particular bar.
- The letter W with the number 70 indicates that the bar type of this saw is a professional bar and does have a replaceable tip.
Consider the following tables for a better understanding of chainsaw chain numbers.
PREFIX INDICATION
| Prefix | Brand |
|---|---|
| S | Stihl |
| SS | Stihl Hard Nose Bar |
| PO | Poulan and other brands that use their mount |
| HJ, HV | Husqvarna and other brands that use their mount |
| SHJ, SHV | Husqvarna hard nose bar and other brands that use their mount |
GAUGE INDICATION
| Stamped Number on Chain | Bar Gauge |
|---|---|
| 50 | 0.050 inches |
| 65 | 0.065 inches |
BAR TYPE INDICATION
| Suffix | Bar Type | Replaceable Tip |
|---|---|---|
| No Letter or Blank | Laminate bar | No |
| FP | Platinum Professional Bar | Yes |
| W | Professional Bar | Yes |
PITCH INDICATION
Pitch is not necessarily stamped on every bar. Mostly Husqvarna bars are the ones that have the pitch stamped as well.
| Stamped Value | Pitch |
|---|---|
| 35 | 0.325 inches |
| 38 | 3/8 inches |
| 46 | 4/6 inches |
How Are Pitch and Gauge Calculated?
GAUGE – It is basically the value of the drive link’s thickness. Measuring the drive link portion that fits inside the guide bar groove provides the measurement of the gauge. It is measured in inches or millimeters.
PITCH – The overall size of the chain is actually the pitch. Measuring the distance between rivets of the drive link and then dividing it by 2 provides the measurement of the pitch.
Note: Drive sprockets and guide bar tips should have the same pitch as that of the chain.
You may read different chain codes here.
Where to Find Chain Number Markings
For most of the chainsaw chains, their numbers are stamped right where the bar mounts to the saw, which is near the back of the bar.
How to Change a Chainsaw Chain?
In order to replace/change a chainsaw chain, here are some simple steps to follow.
- Side panels for guide bars should be removed first. You’ll need to unscrew the nuts and then take off the plate in order to access the old chain that needs to be replaced. In case your chainsaw’s brake is attached to the side panel, you must unlock the brake first and then remove the side panel.
- Now that you’ve taken off the plate, pull the bar out from the chainsaw and it will be released from the tensioner.
- Remove the old chain.
- Next, you have to install the new chain. To make it easier, try to find the tensioning screw which is located on the guide bar inside. When you locate it, loosen the screw. This makes placing on the new chain easier.
- Now thread your new chain onto the clutch drum. The drive links must engage in the sprocket.
- As you’ve threaded the new chain, put the guide bar back onto the chainsaw and adjust it onto the chainsaw’s adjustment pin that you’ll find on the bar.
- Put back on the side plate that you took off at the start, tighten the chain to adjust the tension on it, and place back the side plate nuts.
- This is it. You’re done with changing a chainsaw chain!
Chainsaw Chain Numbers – FAQs
Conclusion
In a nutshell, chainsaw chain numbers indicate the pitch and gauge measurements of the chain. With the help of these measurements, you can easily replace your current chain because you’d know the exact measurements for the new chain that you need!
You may read the chain markings for Husqvarna, Oregon, and Carlton chainsaws from this table chart.
