How to Correctly Select Tooth Pitch (TPI)

A fundamental guide for band saws: extending life, cutting speed, and perfect precision.

What is TPI and the "Gullet"?

TPI (Teeth Per Inch) is the number of teeth per inch (25.4 mm). But it's not just a number.

By choosing TPI, you are choosing the volume of the gullet (interdental space). This is the space that must accommodate all the chips removed in one pass.

  • Small TPI (3/4): Large teeth, deep gullets. For large workpieces.
  • Large TPI (10/14): Small teeth, shallow gullets. For tubes and thin profiles.
1 Inch (25.4mm) TPI = Number of Tips
⚠️ The Golden Rule of "Three Teeth"

There must be at least 3 and no more than 24 teeth in the material at the same time.

Less than 3
Tooth Strippage (Shock)
6 - 12 Teeth
Ideal Cut (Optimum)
More than 24
Overheating & Clogging

Pitch Types: Constant vs Variable

🔢 Constant

Marking: 4, 6, 14

Teeth are at equal distances. Used for wood, aluminum, and short-chip materials.

❌ Causes strong vibrations ("singing") on steel.

🔀 Variable

Marking: 3/4, 4/6, 10/14

Tooth size alternates. This is the standard for metal cutting.

✅ Dampens vibrations, increases life and speed.

Selection Tables (Interactive)

🔵 For Solid Metal (Round, Square)

The larger the diameter, the larger the tooth (smaller TPI number).

Workpiece Diameter (mm) Pitch (TPI) Note
up to 10 mm 14 or 10/14 Wire, rods
10 – 25 mm 10/14 or 8/12 Anchors, bolts
25 – 40 mm 8/12 or 6/10 Small shafts
40 – 80 mm 5/8 or 4/6 Standard
80 – 120 мм 4/6 or 3/4 Medium rolled stock
120 – 250 мм 2/3 Large forgings
> 250 мм 1.4/2 Heavy machinery

🟠 For Pipes and Profiles

The critical parameter is wall thickness (S), not diameter.

Wall Thickness S (mm) Pitch (TPI) Note
up to 2 mm 14 Thin-walled pipes
2 – 4 мм 10/14 Furniture tube
4 – 6 мм 8/12 or 6/10 Angles, channels
6 – 10 мм 5/8 or 4/6 Load-bearing structures
10 – 20 мм 4/6 or 3/4 Thick-walled pipes
Bundle Cutting: If cutting multiple pipes together, sum the wall thicknesses (2S) and add a margin. It's better to choose a slightly larger pitch (e.g., 3/4 instead of 4/6).

🕵️ Diagnosis: What do the chips say?

🌀
Silver
Bright, loosely curled
Ideal mode. Heat goes into the chips.
🔥
Blue / Purple
Overheating
High speed or tooth too fine.
🧂
Thin (Dust)
Underload
Low feed. The tooth rubs instead of cutting.
➰
Thick / Compressed
Overload
High feed or gullet too small.

🛡️ Mandatory Break-In Procedure

A new blade has a sharp but brittle edge. Without break-in, it will lose 50% of its life in the first few minutes.

  • Reduce Speed
    Set blade speed to 70% of normal.
  • Reduce Feed
    Set downfeed rate to 50%.
  • Cut for 15-20 min
    Or cut ~300-500 cm² of material in gentle mode.
  • Ramp Up
    Gradually increase parameters to recommended.