Key Information on a Chainsaw Bar

To read a chainsaw bar effectively, you need to identify key markings that ensure compatibility with your chainsaw chain. These markings typically include the chain pitch, drive link count, chain gauge, and the bar's cutting length.

Chainsaw bars are usually stamped or etched with a series of numbers and letters, often near the base where the bar attaches to the powerhead. Understanding these codes is crucial for safe and efficient operation.

1. Chain Pitch

The chain pitch indicates the size of the chain. It's the distance between three consecutive rivets on the chain, divided by two. This measurement ensures the chain's teeth properly engage with the sprocket on your chainsaw and the nose sprocket on the bar.

• Reference Insight: As highlighted in the provided video snippet, one common pitch marking is "38", which signifies a 3/8" (0.375") pitch. The speaker notes this relates to "the size of the Cutters."
• Common Pitches:
  • 1/4" (.250"): Small, light-duty chains.
  • .325": Popular for homeowner and professional saws up to medium size.
  • 3/8" (.375"): Very common for a wide range of saws, from homeowner to professional.
  • .404": Heavy-duty chains, typically for large professional saws.

2. Drive Link Count

The drive link count specifies the exact number of drive links your chain needs to properly fit the bar. Drive links are the small, triangular or rectangular projections on the bottom of the chain that ride in the bar's groove and engage with the saw's drive sprocket.

• Reference Insight: The video clearly states, "And it's 72 Drive links right there." This directly gives an example of the drive link count you might find stamped on a bar. The speaker emphasizes that "each one of these is a drive links," pointing to their importance.
• Importance: Getting this number correct is critical. Too few, and the chain won't fit; too many, and it will be too loose.

3. Chain Gauge

The chain gauge refers to the thickness of the drive links, which must match the width of the groove in the chainsaw bar. A mismatch can lead to poor performance, excessive wear, or even dangerous chain derailment.

• Common Gauges:
  • .043" (1.1mm)
  • .050" (1.3mm): Very common.
  • .058" (1.5mm)
  • .063" (1.6mm): Common for professional saws.

4. Bar Length (Cutting Length)

The bar length, or cutting length, is the usable portion of the bar that extends from the front of the chainsaw's powerhead to the tip of the bar. It's typically measured in inches or centimeters. While not always directly stamped as a single number (like "20" for 20 inches), it's intrinsically linked to the drive link count, as different lengths require different numbers of drive links.

• Measurement: Measure from the tip of the bar to where it enters the chainsaw housing.

Why is Reading Your Chainsaw Bar Important?

• Safety: Using the wrong chain can lead to kickback, chain derailment, or breakage.
• Performance: A correctly matched chain and bar ensure optimal cutting efficiency and reduced wear on components.
• Compatibility: Ensures you purchase the correct replacement chain or a compatible bar for your chainsaw model.

How to Find the Markings

Chainsaw bar markings are typically located at the tail end of the bar, near the mounting holes, or along the side. They may be stamped into the metal or printed on a label. Sometimes, a magnifying glass can help decipher worn markings.

Summary of Chainsaw Bar Markings

Understanding these markings empowers you to select the correct chainsaw chain for your specific bar, ensuring safe and effective operation.