Tips for successful and safe bandsawing

Bandsaws are powerful machines used in various applications and industries, from aerospace and automobile manufacturing to medical device industries and much more. These machines are efficient at cutting metal and other industrial materials into whatever shape is needed.

As with other industrial machines, bandsaws must be used properly for the best results. With a clear understanding of this tool's capabilities, parts and functions, you can learn how to use a bandsaw safely and efficiently for your cutting projects.

Types of Bandsaw

Industrial metal-cutting bandsaws come in tabletop and standing varieties for different jobs. The three main types of bandsaws have different levels of operator involvement:

1. Manual bandsaws: These bandsaws require you to move the material manually.
2. Semi-automatic bandsaws: Semi-automatic bandsaws only require the operator to select the feed rate and blade speed and place the material — then the bandsaw makes the cuts.
3. Automatic bandsaws: Bandsaws with automatic operation take the operator entirely out of the process by running on preset cut settings.

Bandsaw Blade Selection

Here are some tips on how to make the correct selection of band saw blades. What we have written here applies to commercial bandsaw types with wheels at least 14” (350mm) diameter. It should be noted that while the same selection criteria apply for other types, the range of blades to fit ‘hobby’ band saws is far more restricted.

Blade Thickness

The rule of thumb is simply that the thickness (gauge) of a bandsaw blade should not be a greater than 1/1000th of the wheel diameter of the machine it is to fit, i.e .if you have a 350mm wheel, the maximum thickness run should be 0.035mm.
Blade width is measured from the tips of the teeth to the back of the blade
For straight and cut off work, the blade should be as wide as your machine will allow, as the wider the band, the straighter the cut will be.

For contour sawing, while the blade should be as wide as the machine allows, it should be narrow enough to cut the desired shape or radius.

Exceeding this thickness will cause the band to prematurely crack across the gullets. This is why standard bandsaw blading should never be fitted to a hobby type machine. Blades for hobby machines are normally imported in pre -welded loops to fit a specific machine, whereas blading for industrial machines is imported in 100’ coils ready to be cut to length, welded and annealed.

Blade Width

The most common Industrial bandsaw blading widths begin at ¼”, 3/16”, 3/8”, ½”, 5/8”, ¾”, 1”, 1 ¼”, 1 ½”. (From 6.3mm up to 35mm).

While the correct width will be primarily determined by the minimum radius you need to cut – see chart below.

Ensure the width you select is no greater than ¾ of the wheel width so that the ‘set’ on the band does not damage the wheel surface. The most common widths for General Purpose work are ¼”, 3/8” and ½” with wider bands used primarily for accurate rip cuts.

Blade TPI (teeth per inch)

The number of teeth per inch (TPI) is generally determined by the nature and thickness of the material you’re cutting.

It is a good idea to try to have at least 3 teeth in the work at any time e.g. When cutting 20-30mm stock use 4tpi or if you’re cutting bowl blanks or thicker material you might choose 3tpi. For fine finish work in wood 6 tpi is not uncommon.

6tpi is often used on aluminium with 6 or 8tpi for plastics and hard acrylics, often with a lubricant. Finer pitches are normally reserved for harder metals.

For deep ripping cuts it is good to keep in mind that the wider the band, the straighter it will cut – with the proviso that the guides on your machine are adequate for the width selected. 3tpi is good for shallow ripping up to a max of 150mm but for serious rip cuts of 200mm, 2 tpi is better and for deeper rips 1tpi or even coarser is recommended.

Steel cutting bandsaw blades are generally of finer pitch from 10 tpi and finer. Variable pitch HSS Bimetal is used in high production or heavy duty engineering applications.

The number of teeth per inch (TPI) is important to obtain the desired finish and the proper feed rate.

Suggestions

• Coarse tooth blades (1, 2,3 tpi) should be used for resawing wood and thick stock up to 8”(200mm)
• Medium toothed blades (4,6 tpi) are used as a general purpose blade for wood, some plastics and aluminium (6, 8tpi). More teeth tends to induce melting when cutting plastics and acrylic
• Fine toothed blades (10-32 tpi) are used for cutting thin metals
• More tpi gives a smoother but generally slower cut
• Fewer tpi allow a faster cut with a slightly rougher finish
• Variable pitch blades are used when cutting a wide variety of thickness metals (please inquire).
• Use band knife to cut vinyl, rubber, leather and similar flexible materials (please inquire) 

Blade Material

There are now more blade choices than ever, keeping up with the constant development of new materials and the necessity to cut contours and shapes in them.

• CV Hardened Tooth – standard blades used traditionally for cutting wood and plastics
• HSS Welded Edge (Bimetal) – for abrasive wood types, some composites (dry) and steel (with coolant)
• Tungsten Tipped – for composites, abrasive woods
• Tungsten Grit – for composites, carbon fibre, ceramics

Tooth Geometry

Your blade's teeth determine its cut quality and efficiency and impact blade life. Take a look at the three most common tooth types: 

• Hook tooth blades: These teeth have increased set and open gullets. They are ideal for cutting non-ferrous metals, plastics and softer, sticky materials. 
• Wavy and raker-set tooth blades: This blade is often used to cut ferrous metals. 
• Skip tooth blades: Skip tooth blades have wide gullets to provide improved chip clearance. This tooth style is often used for wood and plastics. 

How to order:

1. Select Blade Type:
 - Standard Carbon Steel, HSS Bimetal or Tungsten Tipped
2. Select Blade Width
3. Select Tooth Pitch:
 - Standard straight pitch TPI - 18, 14, 12, 10, 8, 6, 4, 3, 2, 1, coarser (specify)
 - Variable Pitch TPI 1-2, 2-3, 3-4, 6-8, 8-10, 10-12, finer
4. Select Blade length (mm)
5. Select Quantity
6. Call 0800 488 647, let us know your specification and we look after it for you from then on

Bandsaw Maintenance Tips

You can do a lot to maintain your bandsaw and increase safety when operating it, including the following: 

• Replace throat plates often: Bandsaw throat plates prevent splinters from wedging inside the blade and jamming its movement. Replace throat plates regularly, especially if they are damaged.
• Adjust your blade guards: A bandsaw's blade guides should be right above the material to be cut to prevent unnecessary side strain on the blade. Adjust your blade guard on each cut for optimal performance.
• If practical, lubricate. A felt wiper mounted to rub the sides of the blade while cutting will help to minimise clogging. You can use kerosene or even water as lubricant.
• Clean blades regularly: Clean your blades monthly at a minimum, although biweekly or even more frequent cleaning is better. Use oven cleaners, rust removers or degreasing agents to remove resin and grime. 

Do you have more questions? 

Every day our team strives to boost your confidence, productivity and results through our accurate service and tailored support. Feel free to contact us on  0800 488 647 or sales@tungstenandtool.co.nz to find out more information on premium bandsaw blades.