A chainsaw is a powerful and versatile tool that has become an indispensable part of many industries and household tasks. Among the various sizes available in the market, the 20 – inch chainsaw holds a unique position. It strikes a balance between power and maneuverability, making it suitable for a wide range of applications. This article will delve deep into the world of 20 – inch chainsaws, exploring their design, features, applications, maintenance, and more.
Design and Construction
Engine
The engine is the heart of any chainsaw, and in a 20 – inch chainsaw, it plays a crucial role. Most 20 – inch chainsaws are equipped with either gas – powered or electric engines. Gas – powered engines are typically two – stroke engines. These engines are known for their high power – to – weight ratio, which is essential for a chainsaw that needs to cut through thick branches and logs. The two – stroke engine works by combining fuel and oil in the combustion chamber. The fuel provides the energy, while the oil lubricates the moving parts.
Gas engines in 20 – inch chainsaws usually have a displacement in the range of 30cc to 60cc. A larger displacement generally means more power, but it also increases the weight and noise level of the chainsaw. For example, a 40cc gas engine can provide sufficient power for most residential and light commercial applications, such as cutting firewood or pruning small trees.
Electric engines, on the other hand, are available in both corded and cordless variants. Corded electric chainsaws are connected to a power outlet, providing a continuous source of power. They are often lighter and quieter than gas – powered chainsaws, making them ideal for indoor use or in areas where noise is a concern. Cordless electric chainsaws are battery – powered, offering greater portability. However, the runtime of cordless chainsaws is limited by the battery capacity, which typically ranges from 30 minutes to an hour, depending on the model and the type of battery used.
Bar and Chain
The bar and chain are the cutting components of a chainsaw. The bar is the metal plate that guides the chain as it rotates. In a 20 – inch chainsaw, the bar is, as the name suggests, 20 inches long. The length of the bar determines the maximum diameter of the log that the chainsaw can cut. A 20 – inch bar can handle logs with a diameter of up to about 18 inches, depending on the type of wood and the sharpness of the chain.
The chain is a loop of metal with sharp teeth that cut through the wood. The teeth are designed in different shapes and sizes, each optimized for a specific type of cutting. For example, chipper teeth are commonly used in 20 – inch chainsaws for general – purpose cutting. These teeth have a sharp point and a flat top, which allows them to cut through wood quickly and efficiently. The pitch of the chain, which is the distance between the centers of three consecutive rivets, is also an important factor. A common pitch for 20 – inch chainsaws is 0.325 inches, which provides a good balance between cutting speed and smoothness.
Handles and Controls
The handles of a 20 – inch chainsaw are designed for comfortable and safe operation. Most chainsaws have a left – hand grip and a right – hand grip, which are ergonomically shaped to reduce hand fatigue during prolonged use. The left – hand grip often has a throttle lockout feature, which prevents accidental activation of the throttle. This is an important safety feature that helps to prevent injuries.
The controls on a 20 – inch chainsaw include the throttle, the choke, and the on/off switch. The throttle is used to control the speed of the engine, allowing the operator to adjust the cutting power as needed. The choke is used to enrich the fuel – air mixture when starting a cold engine. Once the engine is running, the choke is turned off. The on/off switch is a simple mechanism that turns the chainsaw on and off.
Safety Features
Safety is of utmost importance when using a chainsaw, and 20 – inch chainsaws are equipped with several safety features. In addition to the throttle lockout mentioned earlier, many chainsaws have a chain brake. The chain brake is designed to stop the chain from rotating in case of a kick – back. Kick – back occurs when the nose of the bar hits an object, causing the chain to suddenly move forward and potentially injure the operator. The chain brake can be activated manually by the operator or automatically in some models.
Some 20 – inch chainsaws also have a safety throttle, which requires the operator to apply a certain amount of pressure on the throttle before the engine can rev up. This helps to prevent accidental acceleration. Additionally, many chainsaws have a chain catcher, which is a small metal plate located below the bar. The chain catcher catches the chain in case it comes off the bar, preventing it from flying out and causing injury.
Applications
Residential Use
In a residential setting, a 20 – inch chainsaw can be a valuable tool. It can be used for a variety of tasks such as cutting firewood. Many homeowners have fireplaces or wood – burning stoves, and a 20 – inch chainsaw can easily cut through firewood logs to the appropriate size. It can also be used for pruning trees and shrubs. Whether it’s trimming back overgrown branches or removing dead limbs, a 20 – inch chainsaw provides the necessary power and precision.
Another common residential application is storm cleanup. After a storm, there may be fallen branches and trees in the yard. A 20 – inch chainsaw can quickly and efficiently remove these obstructions, restoring the yard to its normal state. It can also be used for building decks and fences. The chainsaw can be used to cut lumber to the desired length, making it easier to assemble the structure.
Commercial Use
In the commercial sector, 20 – inch chainsaws are widely used in the logging industry. They are suitable for cutting small to medium – sized trees in logging operations. The chainsaw can be used to fell trees, limb them, and buck them into smaller logs. Its 20 – inch bar length allows it to handle a good range of tree diameters, making it a versatile tool in the logging process.
Landscaping companies also use 20 – inch chainsaws for a variety of tasks. They can use it to shape trees, remove dead trees, and clear brush. Arborists, who are professionals specializing in tree care, also rely on 20 – inch chainsaws. They use it for precision pruning, as well as for removing hazardous branches from trees in public areas.
Emergency Services
Firefighters and emergency responders may also use 20 – inch chainsaws in certain situations. During a wildfire, they may need to cut through vegetation to create firebreaks, which can help to stop the spread of the fire. In search and rescue operations, a 20 – inch chainsaw can be used to remove obstacles such as fallen trees or debris to access trapped individuals.
Maintenance
Regular Cleaning
Proper maintenance is essential to keep a 20 – inch chainsaw in good working condition. One of the most important maintenance tasks is regular cleaning. After each use, the chainsaw should be wiped down to remove dirt, sawdust, and sap. The air filter should be checked and cleaned or replaced as needed. A dirty air filter can reduce the airflow to the engine, leading to poor performance and increased emissions.
The spark plug should also be inspected regularly. A fouled spark plug can cause the engine to misfire or not start at all. If the spark plug is dirty or damaged, it should be cleaned or replaced. The guide bar and chain should be cleaned to remove any debris that may have accumulated. This helps to prevent rust and ensures smooth operation of the chain.
Sharpening the Chain
Sharpening the chain is another crucial maintenance task. A dull chain not only makes cutting more difficult but also increases the risk of kick – back. There are two main methods for sharpening a chainsaw chain: manual sharpening and using a chainsaw sharpener.
Manual sharpening requires a file and a guide. The operator uses the file to sharpen each tooth of the chain according to the manufacturer’s specifications. This method can be time – consuming but allows for more control over the sharpening process. A chainsaw sharpener, on the other hand, is a power – driven tool that can quickly and easily sharpen the chain. It is a good option for those who want to save time or are not comfortable with manual sharpening.
Chain Tension Adjustment
Proper chain tension is essential for the safe and efficient operation of a 20 – inch chainsaw. A chain that is too loose can come off the bar, while a chain that is too tight can put excessive stress on the engine and the bar. To adjust the chain tension, locate the tension adjustment screw or knob on the chainsaw. Turn the screw or knob to tighten or loosen the chain as needed. The chain should be tight enough that it cannot be easily lifted off the bar with a finger, but not so tight that it binds.
Engine Maintenance
The engine of a 20 – inch chainsaw also requires regular maintenance. For gas – powered chainsaws, the fuel should be drained from the tank if the chainsaw is not going to be used for an extended period of time. This helps to prevent the fuel from going stale. The carburetor may need to be cleaned or adjusted from time to time to ensure proper fuel – air mixture.
For electric chainsaws, the battery should be properly maintained. If it is a rechargeable battery, follow the manufacturer’s instructions for charging and storing the battery. Avoid overcharging or discharging the battery, as this can reduce its lifespan. Additionally, the electrical components of the chainsaw, such as the cord and the on/off switch, should be inspected regularly for any signs of damage.
Safety Tips
Personal Protective Equipment
When using a 20 – inch chainsaw, wearing appropriate personal protective equipment (PPE) is essential. This includes safety goggles to protect the eyes from flying wood chips and debris. Ear protection, such as earplugs or earmuffs, is necessary to protect the ears from the loud noise generated by the chainsaw. A hard hat can protect the head from falling branches, and gloves can provide a better grip on the chainsaw and protect the hands from cuts and abrasions.
Chainsaw chaps or pants are highly recommended. These are made of a special material that can stop the chain in case it comes into contact with the leg, significantly reducing the risk of serious injury. Steel – toed boots with good traction are also important to protect the feet and provide stability while operating the chainsaw.
Operating Techniques
Proper operating techniques are crucial for safe and efficient use of a 20 – inch chainsaw. When starting the chainsaw, make sure it is on a stable surface. Never start the chainsaw while holding it in your hands without proper support. When cutting, maintain a firm grip on the chainsaw and keep a stable stance. Avoid cutting above shoulder height, as this can make it difficult to control the chainsaw and increases the risk of injury.
Be aware of the kick – back zone of the chainsaw, which is the area around the nose of the bar. Keep your body and hands out of this zone while cutting. If possible, use a push stick or other safety device when cutting small pieces of wood to keep your hands away from the chain.
Environmental Awareness
Operators should also be aware of their surroundings when using a 20 – inch chainsaw. Be cautious of overhead power lines and avoid cutting near them. Make sure there are no people or animals in the immediate area before starting to cut. Also, be aware of the potential for fire hazards, especially when cutting dry wood. Have a fire extinguisher nearby and follow any local fire safety regulations.
Conclusion
A 20 – inch chainsaw is a powerful and versatile tool that has a wide range of applications in both residential and commercial settings. Its design and construction, including the engine, bar and chain, handles and controls, and safety features, are all carefully engineered to provide efficient cutting performance and user safety.
Proper maintenance is essential to keep the chainsaw in good working condition. Regular cleaning, sharpening the chain, adjusting the chain tension, and maintaining the engine are all important tasks that help to extend the lifespan of the chainsaw and ensure its optimal performance.
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