Customer review 9.6!Choosing the tooth pitch: what does TPI mean and how many teeth do you need?
What does TPI mean on a bandsaw blade? How to convert TPI to tooth pitch in mm, and how to choose the tooth pitch for the thickness of your material.
TPI stands for teeth per inch: the number of tooth tips on 25.4 mm of bandsaw blade. The higher the number, the finer the teeth. The tooth pitch says the same thing as a distance, in millimetres from tooth tip to tooth tip. Which tooth pitch you need depends on the thickness of what you cut; our table is below.
From TPI to tooth pitch in millimetres
Divide 25.4 by the TPI and you have the tooth pitch. At 4 TPI the tooth tips are 6.4 mm apart, at 14 TPI 1.8 mm.
| TPI | Tooth pitch |
|---|---|
| 2 | 12.7 mm |
| 3 | 8.5 mm |
| 4 | 6.4 mm |
| 6 | 4.2 mm |
| 8 | 3.2 mm |
| 10 | 2.5 mm |
| 14 | 1.8 mm |
| 18 | 1.4 mm |
| 24 | 1.1 mm |
| 32 | 0.8 mm |
Our table for wood and plastic
This table comes with Flexback, Hardpoint and Chrome steel. It is based on the thickness of the material.
| Material thickness | Tooth pitch |
|---|---|
| up to 1 mm | 24 TPI |
| 1 to 2 mm | 18 TPI |
| 2 to 2.5 mm | 14 TPI |
| 2.5 to 6 mm | 10 TPI |
| 6 to 10 mm | 8 TPI |
| 10 to 18 mm | 6 TPI |
| 18 to 25 mm | 4 TPI |
| 25 to 38 mm | 3 TPI |
| 38 to 50 mm | 2 TPI |
| 50 to 127 mm | 1.3 TPI |
| 127 mm and thicker | 1.1 TPI |
Coarser than 2 TPI we only make the Ripper, for sawing planks from logs. In 27 mm wide it has a tooth pitch of 19 mm (1.3 TPI), in 32, 35 and 38 mm wide 22 mm (1.15 TPI).
How many teeth are in the material?
Work it out as thickness times TPI, divided by 25.4. A 15 mm board with 6 TPI, as the table suggests: 15 × 6 / 25.4 is just over 3.5 teeth. From 6 to 50 mm thick, our table works out at roughly two to four and a half teeth in the material at once. With thin material that is no longer possible, not even with 24 TPI; there the table gives the finest tooth pitch.
The same board with 2 TPI gives 1.2 teeth. Then the teeth are likely to snag and the blade starts to judder. With 24 TPI there are 14 teeth in the board. The gullets between the teeth can then fill with sawdust before they leave the workpiece, and the cut heats up.
Metal: a variable tooth pitch
Bimetal blades usually have a variable tooth pitch, such as 5/8 or 10/14. The distance between the teeth then varies within that range, which helps against vibration. For tube and profiles you go by the wall thickness, for solid metal by the cross-section. The tables for that are in cutting stainless steel and steel with a bandsaw.
Too coarse or too fine: how to tell
A tooth pitch that is too coarse often shows as vibration or juddering, and as edges of thin material breaking out. On thin tube, teeth can break off.
A tooth pitch that is too fine shows as slow cutting and sawdust staying in the cut. The material can heat up, some plastics start to melt, and the teeth wear faster.
Which tooth pitch in which width?
Not every tooth pitch is available in every width. Flexback goes from 32 TPI, only in 6 and 13 mm wide, to 2 TPI from 20 mm wide. Hardpoint has 2 to 6 TPI, Chrome steel 2 to 10 TPI. Bimetal M42 has 2/3 to 10/14 TPI, and in 13 mm wide also 4, 6 and 18 TPI.
The configurator on each product page shows which tooth pitch is available for each width. How to determine length, width and thickness is explained in choosing the right bandsaw blade, and the selection tool helps you find the type in two steps.