The seemingly straightforward question of “what chainsaw takes a 72-link, 20-inch bar” unlocks a deeper exploration into the intricate world of chainsaw specifications and their direct impact on performance, application, and overall user experience. This isn’t merely about finding a single model; it’s about understanding the engineering behind the tool, the crucial role of chain length and bar size, and how these elements dictate a chainsaw’s capabilities. For enthusiasts, professionals, and even discerning homeowners, a thorough grasp of these specifications is paramount to selecting the right equipment for the job, ensuring efficiency, safety, and longevity.
This article delves into the technical considerations that define chainsaw compatibility with specific bar and chain lengths. We will explore the common reasons why a 72-link chain and a 20-inch bar are a popular pairing, the factors that influence this choice by manufacturers, and how to identify chainsaws that are designed to accommodate these dimensions. Ultimately, this knowledge empowers users to make informed decisions, optimize their chainsaw’s performance, and avoid common pitfalls associated with mismatched components.
Understanding the Core Components: Bar and Chain Dynamics
At the heart of any chainsaw’s cutting capability lie the bar and the chain. These two components work in tandem, with the bar guiding the chain’s movement and the chain, with its sharp teeth, performing the actual cutting. The interplay between their sizes and specifications is critical for optimal performance and safety.
The Bar: The Guide and the Framework
The chainsaw bar is essentially a hardened steel guide that the chain travels around. Its length, measured in inches, is a primary indicator of the maximum cutting capacity of the chainsaw. A longer bar allows for deeper cuts and the felling of larger diameter trees or the processing of substantial logs. However, longer bars also demand more power from the chainsaw’s engine and can be heavier, affecting maneuverability.
The design of the bar also plays a role. Most bars have a standard mounting pattern that connects to the chainsaw’s powerhead. Different manufacturers and even different chainsaw series within a manufacturer may have slightly varying mounting interfaces. This is a critical consideration when selecting a replacement bar or assessing compatibility. Furthermore, the bar’s tip radius influences kickback potential. Narrow-radius bars generally have a smaller sprocket nose, reducing the likelihood of the chain snagging and causing dangerous kickback.
The Chain: The Cutting Edge
The chainsaw chain is a complex loop of metal links, each equipped with sharp cutters. The chain’s specifications are equally important as the bar’s. The two most critical metrics for a chain are its pitch and its gauge.
- Pitch: This refers to the distance between the drive links (the part that sits in the bar groove) and is typically measured from the center of one rivet to the center of another, then divided by two. Common pitches include .325″, 3/8″, and .404″. A larger pitch generally signifies a more aggressive chain designed for heavier-duty cutting.
- Gauge: This is the thickness of the drive links, which must match the width of the groove in the guide bar. Common gauges are .050″ and .063″. Using a chain with the incorrect gauge will prevent it from fitting the bar properly, or worse, cause damage to both components.
Beyond pitch and gauge, the number of links is the final piece of the puzzle for chain compatibility with a specific bar and chainsaw. This is where our core question of “72 links” comes into play.
The Crucial Link Count: Why 72?
The number of chain links, specifically the drive links that engage with the sprocket and fit into the bar groove, is dictated by the length of the bar and the pitch of the chain. A longer bar requires more chain links to complete its loop. Conversely, a shorter bar requires fewer links. The 72-link count, when paired with a 20-inch bar, suggests a specific combination of chain pitch and bar geometry that manufacturers have standardized for certain engine sizes and intended applications.
When you see a recommendation for a 72-link chain with a 20-inch bar, it’s usually an indication of a well-balanced system. A 20-inch bar is a versatile size, suitable for a wide range of tasks from limbing and bucking smaller to medium-sized trees to felling somewhat larger timber. For this length and the associated cutting demands, a 72-link chain, often in conjunction with a common pitch like 3/8″ or .325″ (depending on the saw’s power and target market), provides the optimal number of cutters to engage with the wood efficiently without overworking the engine or creating excessive tension.
Identifying Chainsaws Compatible with 72-Link, 20-Inch Bars
Finding a chainsaw that accommodates a 72-link, 20-inch bar involves understanding manufacturer specifications and recognizing common configurations. While the bar length is often advertised, the chain link count is less frequently highlighted, making it a detail that requires a bit more investigative work.
Manufacturer Specifications and Model Research
The most reliable way to determine compatibility is to consult the manufacturer’s official specifications for a given chainsaw model. This information is typically found in the owner’s manual, on the product’s page on the manufacturer’s website, or in technical data sheets. Look for sections detailing “guide bar length” and “chain specifications,” which will often list the recommended chain pitch, gauge, and the number of drive links.
When researching, pay close attention to models designed for mid-range to professional use. Chainsaws with engine displacements in the 50cc to 70cc range are commonly paired with 20-inch bars and chains that utilize around 72 drive links. This is because these engine sizes offer sufficient power to drive a 20-inch bar effectively without being overly cumbersome for the operator.
Some popular chainsaw brands known for offering models that commonly utilize 72-link, 20-inch bar configurations include:
- Stihl: Models in their professional or farm & ranch series, such as certain iterations of the MS 261, MS 271, MS 362, and potentially some older or specialized models.
- Husqvarna: Look towards their professional series, including models like the 350, 450 Rancher, 550 XP, or similar engine-sized counterparts.
- Echo: Their professional-grade chainsaws, often found in the CS-590, CS-600P, or CS-620P lineups, frequently accommodate this setup.
- Poulan Pro / Craftsman: While often positioned more towards the homeowner or occasional user, some of their more robust models can be found with these specifications.
It’s crucial to remember that specifications can vary between model years and regional variations. Always verify the exact model number and its associated documentation.
Understanding Bar and Chain Equivalents and Aftermarket Options
Once you’ve identified a chainsaw model that accepts a 20-inch bar, the next step is confirming its compatibility with a 72-link chain. Often, a 20-inch bar will have a specific chain pitch and gauge. If the chainsaw is designed for a 20-inch bar with a 3/8″ pitch and .050″ gauge, a 72-link chain with those same specifications will be compatible.
Sometimes, a manufacturer might specify a slightly different link count for a 20-inch bar due to subtle differences in their bar or sprocket design. For example, a 20-inch bar with a .325″ pitch might require a different link count than a 20-inch bar with a 3/8″ pitch. However, 72 links is a very common count for 20-inch bars with 3/8″ or .325″ pitch in the mid-sized to professional saw category.
If you’re purchasing a replacement chain and are unsure, it’s best to:
- Check your current chain: The number of links is often stamped or etched onto the drive links.
- Consult your owner’s manual: This is the most definitive source.
- Contact the manufacturer’s customer support: They can often provide specific chain compatibility information based on your chainsaw’s model and serial number.
- Utilize online chain calculators: Many chainsaw parts retailers offer online tools where you can input your bar length, pitch, and gauge, and it will suggest the correct chain link count.
When considering aftermarket bars and chains, ensure they are from reputable brands and are designed to meet or exceed OEM (Original Equipment Manufacturer) specifications. Compatibility is key to preventing damage and ensuring safe operation.
Optimizing Performance with the Right Bar and Chain Configuration
The selection of a 72-link, 20-inch bar and chain isn’t just about finding a compatible set; it’s about optimizing the chainsaw’s performance for its intended applications. This combination strikes a balance between cutting power, speed, and the demands placed on the engine and operator.
Balancing Power, Speed, and Cutting Depth
A 20-inch bar offers a substantial cutting reach, allowing operators to fell medium-sized trees and process larger logs efficiently. The 72-link chain, when appropriately pitched and gauged for this bar length, ensures that the correct number of cutters are actively engaged with the wood. This translates to a smoother, more consistent cut.
- For Felling: A 20-inch bar paired with a 72-link chain is often ideal for felling trees up to 16-18 inches in diameter. The depth of cut is sufficient to make efficient back cuts and face cuts, allowing for controlled felling.
- For Bucking: When cutting fallen trees into manageable lengths, this setup excels. It can power through logs that would be too large for shorter bars while remaining maneuverable enough for intricate work.
- For Landscaping and Arboriculture: Professionals in these fields often rely on this configuration for removing large limbs, clearing brush, or tackling more substantial pruning tasks.
The choice of chain pitch also influences performance. A 3/8″ pitch chain, commonly found with 72 links on a 20-inch bar for mid-to-professional saws, offers aggressive cutting and good chip clearance. A .325″ pitch, sometimes found on slightly smaller but still powerful saws with 20-inch bars and 72 links, provides a slightly less aggressive cut but can be more forgiving and efficient for lighter tasks or when operator fatigue is a factor.
Maintenance and Longevity: The Role of Proper Fitment
The importance of having the correct chain and bar combination cannot be overstated when it comes to maintenance and longevity.
- Chain Tension: A chain with the correct link count will tension properly on the bar and sprocket. An improperly tensioned chain (too loose or too tight) will wear prematurely, increase the risk of derailment (which can damage both the chain and the bar), and put undue stress on the engine’s clutch and drive system. A correctly tensioned chain that fits the bar perfectly will maintain optimal contact, leading to efficient cutting and reduced wear.
- Bar Groove Wear: The drive links of the chain ride within the groove of the guide bar. If the chain gauge is incorrect, or if the chain is the wrong length and is forced to fit, it can lead to uneven wear or damage to the bar groove. This can make it difficult to install new chains correctly and can compromise cutting performance.
- Sprocket Engagement: The drive sprocket on the chainsaw’s clutch engages with the drive links of the chain. The correct chain length ensures proper engagement, allowing the engine’s power to be transferred efficiently to the cutting action.
Regular cleaning of the bar groove, proper chain sharpening, and diligent attention to chain tension are all critical maintenance practices. However, these practices are only truly effective when the fundamental components – the bar and the chain – are correctly matched. A 72-link, 20-inch bar and chain combination, when chosen for a compatible chainsaw, represents a well-engineered system designed for robust performance and reliable operation. By understanding these specifications, users can invest in tools that meet their needs, perform optimally, and last for years to come.
aViewFromTheCave is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates. As an Amazon Associate we earn affiliate commissions from qualifying purchases.