Lumber sawyers, furniture makers, and wooden boat builders have relied on bandsaws for well over a century—and for good reason.
They appear easy to operate but can be very challenging to produce repeatable results. It can rip, crosscut, and saw curves through thick and thin material with less waste and power than any other machine in the shop.
A bandsaw can perform so well that you may wonder why you would need another power saw in the shop.
To harness the full potential of this indispensable tool, understanding its key components is essential. That’s why this guide delves deep into the main parts of a bandsaw and their functions.
How Does a Band Saw Work?
Bandsaws are among the most important tools of the woodshop. Their versatility comes from their narrow, continuous loop of a blade, allowing the saw to make straight and curved cuts.
A band saw works by using a continuously circulating loop of a toothed metal blade to make precise cuts typically, but not limited to, wood. The blade is tensioned between two wheels and is powered by an electric motor. As the blade moves downward, the workpiece on the table is pushed into the blade, allowing for both straight and curved cuts to the workpiece. The speed and feed rate can usually be adjusted.
The band saw’s downward-cutting motion and low speed prevent kickback, which occurs undesirably often with table saws when a workpiece gets picked up by the blade and violently thrown around the shop.
These features place the bandsaw among the most important tools in a woodshop. Let’s take some time to familiarize ourselves with its parts.
Parts of a Band Saw and Their Functions
All bandsaws are essentially the same and are relatively simple machines with easily accessed parts. The schematic diagram below provides an overview of the main parts.
1. Frame & Wheel Housing
The frame is the most important part of a band saw. It supports the wheels, blade guides, table, and sometimes the motor. A stiff frame provides adequate support for tensioning the blade and provides a reliable mount for the blade guides.
The frame material also has to remain stable throughout temperature and humidity changes to ensure accurate alignment of the wheels and guides.
This is the metal band in a continuous loop with cutting teeth on one edge. The blade must be mounted so that the cutting teeth are pointing down. You can learn more about the importance of band saw blade direction here.
Different projects may require specialized blades, such as hook-tooth blades for fast, rough cuts, skip-tooth blades for softer materials, or regular-tooth blades for general-purpose cutting, allowing your bandsaw to adapt to a wide range of woodworking needs.
A bandsaw’s wheels have several important roles: They provide power, support, and guidance for the blade.
The axle for the upper wheel can travel vertically and is equipped with a tensioning screw and spring for tensioning the blade. The spring also acts as a shock absorber, providing some resilience when the blade encounters sudden changes in wood density, resulting in unexpected cutting forces.
The lower wheel drives the blade downward and is either mounted directly to the motor or connected using a drive belt. The wheels are machined to accept a pliable tire around their perimeter. Cast-iron wheels, which are much heavier than aluminum wheels, create a flywheel effect to help maintain consistent blade speeds when cutting through material of varying density.
Some band saws provide axial adjustment for the lower wheel. This allows horizontal and vertical tilting to achieve proper alignment with the upper wheel.
Many bandsaws today come with a quick-release tension lever. This feature reduces the time when changing blades or when releasing the tension on a saw that won’t be used for a while.
4. Drive Mechanism
Motor speeds typically range from roughly 1400 rpm to 1750 rpm, depending on the age of the bandsaw.
Today, manufacturers mostly reduce the speed of the motor but reach the proper blade speed by using two pulleys and a drive belt to act as a transmission. The large pulley is attached to the lower wheel, and the small pulley is attached to the motor.
The big advantage of a separate motor is its ease of replacement if necessary.
Blade guide assemblies above and below the table keep the blade in the desired path, thus preventing inaccurate cuts.
Each guide assembly has a side guide on both sides of the blade and a thrust guide directly behind the blade. The side guide keeps the blade from twisting laterally, while the thrust guide supports the back edge of the blade to counter the resulting force when the workpiece is pushed into the blade.
Thrust guides are crucial for maintaining the strength of the blade during operation.
The upper guide is attached to a height-adjustable guidepost. This allows positioning the guides according to the size of the workpiece to calibrate blade control and increase safety.
6. Table and Accessories
The band saw table supports the workpiece to be cut. It has a removable throat plate and a slit running from the center to the edge to allow for blade changes. A small, tapered pin is typically inserted into a hole bored at the edge of the table to keep the table sections aligned at the slit.
A fixed table alone, however, is not enough, especially when working with larger parts requiring cutting at an angle. Therefore, a semi-circular mechanism called a trunnion supports the table. The trunnion typically allows the table to tilt just past 45º upward and about 10º downward for sawing bevels.
Most tables also have a slot that runs across the table to mount accessories.
To achieve straight cuts along a longer length, a rip fence is used, which also extends from front to back on the table. Most rip fences slide side-to-side on a rail that’s attached to the front of the table.
A good rip fence will allow you to angle the fence diagonally across the tabletop to offset a sawing phenomenon known as blade drift.
If you want to make crosscuts or miters (angled cuts), another tool called the miter gauge can be attached to the slot in the table mentioned earlier. The miter gauge has a protractor-style head that can be angled to make crosscuts or miters on the workpiece.
Few things in life are constant; even the position of the bandsaw in your shop may change. For this, many less-hefty bandsaws come with a mobile base with back wheels for transport.
Dust Collection Port
Band saws create fine sawdust that in time, find their way into the corners of your saw, shop, and lungs. So, dust collection is important, not only for your cleanliness and your health but also to prevent sawdust from gathering on the wheels and guides of your band saw.
Dust collection ports are usually located close to the source of the dust, which is directly below the lower blade guides.
Higher-quality saws include a ramped chamber in the lower housing. This directs the dust toward a dust port.
The weight of larger band saw wheels creates considerable inertia under operation. When the power is shut off, the momentum of the two wheels can keep the saw running for some time, especially when equipped with a narrow blade.
To save time and increase safety, a foot brake is of great help, particularly when frequent stopping is needed to reorient a workpiece or an accessory.
Some foot brakes include a switch that cuts the saw’s power when the brake is applied for an emergency stop.
A band saw’s versatility stems from its narrow, continuous loop of a blade.
Its relatively simple design allows it to do everything from cutting complex shapes of small workpieces and joints to slicing dense boards across their width.