My band saw is cutting out of square. What do you suggest I look at?
Take a look at our Problems and Solutions Reference Guide located on our website. If you need further assistance, feel free to contact customer service.
Which type of band saw blade do I use?
Carbon FlexBack – Low cost blade for plastics, woods, and non-ferrous applications.
Carbon HardBack – Greater rigidity than flexback allows up to 25% more performance
Bi-Metal M42 – Resists heat and wear at higher speeds and feeds
Carbide Tipped – For use with highly abrasive metals and non-metallic composites
Set Tooth – for nonferrous foundry applications such as cutting gates and risers, some exotic applications
Triple Chip – for cutting exotic metals and for high production applications, some nonferrous foundry.
Which tooth pitch should we use?
Number of teeth in the cut:
Minimum – 3 teeth in the cut
If there are too few teeth in the cut, the teeth can straddle the work piece, which can cause stripping.
Maximum – 24 teeth in the cut
Too many teeth in the cut may cause the gullets to “overload”, because there is not enough gullet capacity
The “optimum” TPI is 6 to 12 teeth engaged in the cut at one time
Conditions that influence pitch selection:
- Soft materials: Require fewer teeth and more gullet capacity (Aluminum, Copper, Bronze, Carbon Steels)
- Tough Materials: Use a moderate amount of teeth in the cut – in the 12 to 18 tooth range (Inconel, Hastalloy, Waspalloy, Monel, Steels)
- Hard Materials: Use more teeth in the cut – in the 18 to 24 tooth range (D-2, Die Steels, Stainless Steels)
- Machine capabilities: constant feed machines can use a coarser pitch, whereas gravity feed machines typically require a finer pitch
Production or blade life:
- For production cutting, use tooth pitches near the coarse end of the range
- For good finish or smoother cut surfaces, use finer teeth
- For best blade life, run in the middle to the fine end of the recommended tooth pitch range
What blade speed should we use?
- Material Machinability Rating – The lower the machinability rating the slower the band speed will need to be.
- Blade Selection – The cutting edge (tooth tip) of the blade will govern the speed at which the blade can run (FlexBack = Slowest Cutting, Carbide = Fastest Cutting)
- Cutting Noise / Vibration – Cutting noise or vibration is a killer to a cutting edge – if either is present, the speed must be decreased
- Coolant / Cutting Fluid – If the coolant is adequate, use the standard cutting chart speeds. When cutting dry, reduce the speed by 40-50%
What is the relationship between feed and speed?
- Feed, Speed and Tooth Pitch are directly related.
- To change the cut result, change only one variable at a time.
- Increasing the Work Size will decrease tooth penetration.
- A larger Tooth Pitch will increase tooth penetration.
- A smaller Tooth Pitch will decrease tooth penetration.
- Increasing the Blade Speed will decrease tooth penetration.
- Reducing the Blade Speed will increase tooth penetration.
Why do we need a cutting fluid?
Lubricating the cutting edge will reduce the heat that is generated by cutting friction – too much heat in the cut is one of the main reasons for blade failure.
- A flood of coolant helps wash the chips from the gullets
- Chips become work-hardened in the cutting operation
- If chips are dragged back through the cut a second time, they can damage teeth
- A flood of coolant helps cool the blade’s cutting edge and saw guides, extending blade life.
Remember: flood coolant whenever possible and only use coolant where chips are present – do not use coolant on materials that produce a powder, such as gray iron.
Why do we need to break a band saw blade in?
- New, sharp teeth are more fragile than lightly honed teeth
- Break-in hones the teeth and helps make all teeth the same height
- Proper break-in results in less blade stripping and longer blade life
- Set proper blade speed for the machinability and size of material to be cut
- Reduce the normal feed rate by approximately 50% of the regular rate for the first few square inches
- Watch the chips
Small flakes = Insufficient feed
Heavy blue chips = Excessive feed
Spring curled no color = Proper feed rate
(During break-in, it is important that the band always produces chips)
- As you break-in the blade, graduate the feed rate to 100%.
To learn more about the importance of blade break-in, please take a look at our blog.