Chain Identification Guide:

 

A chainsaw chain is designed to fit a bar and sprocket combination, not a specific powerhead model. 

In mechanical power transmission—specifically regarding chainsaw operation—ambiguity is a safety hazard. Running a chain with incorrect dimensional specifications can lead to failure of the guide bar, the drive sprocket, or the chain itself.

To an engineer, a chainsaw chain is not a single unit, but a series of articulated links subjected to high tensile force and rotational velocity. Identifying the correct replacement requires isolating three specific dimensional variables: Pitch, Gauge, and Drive Link Count.

1. The Primary Variable: Chain Pitch

Definition: Pitch is the average distance between rivets. It dictates the mechanical fit between the chain and the drive sprocket.

  • Why it matters: The pitch determines the size of the chain's "footprint." If the chain pitch does not match the sprocket pitch, the drive links will not mesh correctly, causing rapid wear or derailment. 

  • Common Standards:

    • 1/4": Precision pruning, low vibration.

    • 3/8" Low Profile (Picco): Common on consumer saws; lightweight efficiency.

    • .325": Mid-range saws; balances speed and torque.

    • 3/8" (Standard): Professional forestry; high chip clearance.

    • .404": Heavy-duty harvesters and rescue saws.

 


2. The Tolerance Variable: Chain Gauge

Definition: The gauge is the physical thickness of the drive link's tang (the bottom part that rides in the bar groove).

The Fit Class: This is a clearance fit. The drive link must be slightly thinner than the bar groove to allow for lubrication but thick enough to prevent lateral instability (leaning) during the cut.

  • Common Specifications (Imperial):

    • .043" (1.1mm): Narrow kerf, generally small or battery/electric saws.

    • .050" (1.3mm): The most universal standard.

    • .058" (1.5mm): Common in specific European/Husqvarna applications.

    • .063" (1.6mm): Heavy-duty Stihl applications.

Warning: A .050" chain will physically enter a .058" bar groove, but the excessive lateral clearance will cause the chain to tilt, leading to inaccurate cutting and uneven bar wear. Double check your bar specs.

3. The Length Variable: Drive Link Count (DL)

Definition: The total integer count of drive links in the loop.

Measurement Protocol: Do not measure the "length" of the chain in inches or cm, as chains stretch (elongate) over time due to wear at the rivet interfaces. The only reliable metric for length is the count of drive links.

  • Procedure: Remove the chain. Mark the first drive link with a paint marker or chalk. Count strictly the links that sit inside the bar groove until you return to the mark.

4. Identification Protocol: How to Verify

Before ordering consumables, verify your data using one of the following methods, ranked by reliability:

  1. The Bar Stamp (Primary Source):

    Most guide bars have the technical specifications laser-etched or stamped into the tail (the end closest to the engine). Look for:

    • Pitch (e.g., 3/8 P)

    • Gauge (e.g., 1.3mm / .050")

    • DL (e.g., 55)

  2. The Drive Link Stamp:

    Manufacturers often stamp a code on the drive link itself (e.g., Stihl uses codes like "63" or "3"). You must cross-reference this code with the manufacturer's OEM datasheet to determine the gauge and pitch.

  3. Manual Vernier Measurement:

    If no markings exist, use digital calipers to measure the drive link thickness (Gauge) and measure the distance between three rivets divided by two (Pitch).

 

If you are still unsure of the exact chain specs or have any doubts, please do not hesitate to contact us so we can ensure a perfect fit.