Metal Cutting

When cutting metal on a bandsaw the two important factors are the cutting speed and the tooth pitch.

A lot of wood cutting bandsaws come with 2 speeds and the slower speed is sometimes listed as being for metal cutting - this is sort of true as the slower speed can be used for non ferrous metals (brass, aluminium etc) but is no good for ferrous metal (mild, stainless steel etc).

If the cutting speed is too fast then this will put too much heat into the teeth of the blade and will either cause them to go blunt really fast or the teeth will strip off the blade completely.

Generally the harder the steel, the slower the cutting speed and the following speeds are a rough guide:

  • Aluminium: 150 – 1000m/min
  • Mild Steel: 50 – 120m/min
  • Stainless Steel: 20 – 75m/min

There can be a wide range with the speeds as the quality and thickness of the steel, whether it’s solid or tubed will all make a difference.

When cutting metal with a new blade, it’s important to run the blade in – when a blade is new, the teeth are very sharp but for best results when metal cutting the tip of the tooth needs to be slightly rounded. This is achieved by using a slow feed rate for the first 5 – 10 minutes of cutting, by doing this you will improve blade life and cutting performance.

Another way to improve blade life and cutting performance when cutting metal is to use a cutting fluid, although not all bandsaws have the facility to use cutting fluid and you can cut metal dry, but you will always get better results from using a cutting fluid.

A cutting wax can also be used and can be especially good on non-ferrous metal.

Carbon and M42 are the most popular blades for metal cutting with the M42 being the better option.  They are more expensive but will last around 5 – 10 times longer and will work out a lot cheaper in the long term. Another advantage of the M42 is that they are available in a vari-tooth format where it has 2 different tooth pitches. The vari-tooth format improves cutting performance and will also help in coping with different thicknesses etc.

Similar to wood cutting, the thicker the material being cut, the coarser the tooth pitch required and the thinner the material, the finer the tooth pitch.  With metal cutting, the tooth pitch can also vary depending on whether the material being cut is solid, tubed and the wall thickness if tubed.

For general cutting either the 10/14 or 9/11 from the M42 range or 14tpi from the Carbon range are ideal – these blades will cope with the widest variety of thicknesses and types of metal but here is a chart to help pick the best tooth pitch:


Vari- Tooth

Solid Material 

Pipes/Profiles

2/3 Vari-Tooth

120 to 400mm

Over 20mm

3/4 Vari-Tooth

80 to 150m

12 to 20mm

4/6 Vari-Tooth

10 to 80mm

6 to 12mm

5/8 Vari-Tooth

35mm to 80mm

4 to10mm

6/10 Vari-Tooth

25mm to 60mm

3 to 6mm

8/12 Vari-Tooth

20 to 50mm

1.5 to 3mm

9/11 Vari-Tooth

0.5mm to 30mm

0.5mm to 5mm

10/14 Vari-Tooth

0.5mm to 30mm

0.5mm to 5mm

14/18 Vari-Tooth

Up to 15mm

Below 0.5mm


Straight TPI

Solid Material 

Pipes/Profiles

3tpi

120 to 250mm

Over 20mm

4tpi

80 to 120m

10 to 20mm

6tpi

50 to 80mm

5 to 10mm

8tpi

30mm to 50mm

4 to 6mm

10tpi

15mm to 30mm

1.5mm to 3mm

14tpi

Up to 30mm

Up to 8mm

18tpi

Up to 20mm

Up to 3mm

24tpi

Up to 8mm

Up to 1mm

32tpi

Up to 6mm

Below 0.5mm

Again this is only a guide and it’s not to say that you can’t use a blade for cutting outside of the ranges above. The above ranges will give the best performance for that tooth pitch but if for example you’ve got a 10/14 Vari-Tooth on your bandsaw and you wanted to cut 50mm solid, the blade will do it, just at a slower cut than an 8/12.