How to choose the best bi-metal Bandsaw Blade
With a wide range of Bandsaw blade available in a variety of widths, tooth designs, material applications, and configurations. Choosing the right bandsaw blade for your cutting application is essential. However, as with any industrial job, there are many factors to think about before you even start cutting your material.
Firstly you should be aware of your bandsaw machine capacity, the type of material that you wish to cut, and the skill level of your operator. It’s also important to remember that a small miscalculation can cause damage to the blade or the machine. Before we move any further here are a few terminologies that are related to bandsaw blades.
Before we move any further here are a few terminologies that are related to bandsaw blades.
Bandsaw Blade Terminology
Gullet– The bandsaw blade gullet is the curved area at the base of the blade tooth. It is measured as the distance from the tooth tip to the bottom of the gullet, this is also referred to as ‘gullet depth’.
Kerf– The amount of material removed by the blade from side to side.
Camber– This is the angle of the cutting edge of your bandsaw blade.
Cutting Rate– The Speed at which the material is cut is called the cutting rate, It is measured in square inches per minute.
Feed Rate– The feed rate is the speed that the material is pushed through the blade. It is measured in inches per minute.
TPI/Pitch/Teeth per inch – On a bandsaw, the distance from the tip of one tooth to the next is called the pitch/TPI.
Generally, the bigger tooth, the lower the quality of the surface finish of the cut, because the blade can be a bit unwieldy. It’s generally recommended to have 6 to 8 teeth engaged at one time during a cut. If fewer teeth are engaged, there is a possibility of shaking or vibration that can alter the final product. The bigger the tooth, the greater ability to move big amounts of sawdust during the job, and therefore the faster the cut. Similarly, a smaller TPI will have a slower cut, as it won’t be able to clear as much sawdust
Over time you will confidently know which band saw blade you need for each job, however, if you are a little unsure or require clarification on the correct bandsaw blade that you need to use then consider the following :
Selecting the right Bandsaw blade tooth style and set
Generally, bandsaw blades with different tooth styles are designed for different materials. Elements such as toughness, hardness, materials type, and sectional geometry all contribute to tooth geometry. There are 3 main types, additional types are available for specialized jobs.
Regular tooth– These blades have proportionally spaced teeth. These are ideally used for cutting all ferrous materials along with general-purpose cutting operations. Regular blades tend to have a smooth, rounded gullet at the base of the tooth.
Hook tooth- These blades are commonly used for long cuts in thicker wood, hardwood, and general non-ferrous, and softer metals. Hook tooth form has a positive rake of around 10° and a deeper gullet which helps the blade to feed into the material more aggressively. It results in faster cutting rates.
Skip tooth- These blades, on the other hand, are spaced farther apart than the regular blades and have a rake angle of 0 degrees. This angle prevents the clogging of dust when cutting soft materials, like plastics, softwood, and non-ferrous materials.
Variable pitch- Used as an all-purpose and contouring blade type, The Variable Pitch blades have alternating sets of different-sized teeth and non-uniform distance between them. These are mostly used to reduce chatter and vibration to provide a fast cut with a smooth finish, ideal for joinery and cutting tubular/hollow sections.
Raker tooth blade- These blades have one tooth going one way, the next tooth pointing in the other direction, and a third tooth pointing straight up. The straight tooth is called a ‘raker,’ which also denotes the name of the blade.
Alternative tooth blades- These blades are similar to the raker cut, but they just have teeth pointing in alternate directions, there is no raker tooth in between them.
Wavy tooth blades- These blades have groups of teeth that are set right and left, with an unset tooth in between. These band saw blades have made with fine, small blades, and are used for cutting tubes, thin metal, thin pipes, etc.
How many Teeth(Tooth Pitch)
Tooth pitch is measured in TPI (Tooth per Inch) and can be the main factor when choosing a bandsaw blade, when the pitch is correct you will see a large improvement in cutting performance also resulting in longer blade life.
- Bandsaw blades have a minimum of 2-3 TPI per inch.
- The higher the TPI the finer the tooth pitch
- Cutting thin material such as a lightbox section requires more teeth per inch (fine tooth pitch)
- Coarse pitches are required for thicker materials such as beams or flat bars (lower TPI)
- When using a bandsaw to cut harder materials like stainless steel it is recommended to use one pitch finer than what would be used on mild steel.
Choosing a Blade Set
Choosing a suitable set provides a balance between the blade, air in the space, the body of the saw blade, and the material it is cutting. A suitable set is about 80/20, with 80% sawdust and 20% air being removed. The sawdust should be warm, not hot or cold.
A lot of set results in too much air and not enough sawdust can leave tooth marks.
Too low a set restricts airflow and limits the blade’s ability to draw sawdust from the cut. This leads to hot, packed sawdust and short cutting times, and untimely blade breakage. This is about the worst thing that could happen to a bandsaw blade.
Know the Surface Feet Per Minute (SFM)
Knowing the Surface feet per minute for the different settings of the bandsaw blade helps in selecting the proper speed for the material that has to be cut. Bandsaw blade manufacturers do provide maximum SFM ratings for their blades. It can be found in the SFM settings in the owner’s manual or consult with the manufacturer’s engineers. If the manufacturer is not of much help, then you can use this formula:
Surface Feet per Minute = Drive Wheel RPM x Drive Wheel Diameter x 0.262
Bandsaw blade Size
Using the correct size blade is essential to the performance of the bandsaw blade. If you don’t have a manual and there are no markings on your machine, follow these steps to determine blade length:
- Set the wheels or pulley in the working position.
- Estimate the distance between centers on the drive wheels. (C)
- Estimate the radius of the upper and lower drive wheels. (R1 & R2)
- Measure the blade length with this formula: Blade Length = (R1 X 3.146) + (R2 X 3.146) + (2 X C)
Choosing a Right Bandsaw blade can be difficult. If you want an expert opinion then you can reach out to us by clicking here. Our team of experts can recommend you the best blades that suits your machine and cut the required material.
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