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How to Choose the Right TPI for Your Bandsaw Blade
How to Choose the Right TPI for Your Bandsaw Blade
Choosing the wrong tooth pitch is one of the most common bandsaw mistakes.
Too few teeth in the cut and you get rough, aggressive cuts with chipping. Too many teeth and the gullets pack with chips, generating heat and killing your blade early. The rule is simple: at least 3 teeth must be engaged in the material at all times.
But there's more to it than that.
What Does TPI Mean?
TPI stands for teeth per inch — it's how many tooth tips fit in one inch of blade length. A lower TPI (like 2/3) means bigger, more widely spaced teeth for heavy cuts. A higher TPI (like 14 or 18) means finer teeth for thin material and smoother finishes.
Variable vs Constant Pitch
Some blades use a variable tooth pitch — written as two numbers like 3/4 or 2/3. This means the tooth spacing alternates between the two values. Variable pitch reduces vibration and noise, which is why production blades like the Arntz Sprint-Plus use it. The alternating pattern also helps prevent harmonic resonance that can cause premature blade failure.
Constant pitch blades (like the Arntz CS-1) use evenly spaced teeth — written as a single number like 6 or 10 TPI. These are straightforward and work well for consistent, repeatable cuts on the same material.
Matching TPI to Your Material
Here's a general guide:
| Material Type | Recommended TPI | Why |
|---|---|---|
| Large solid rounds/squares (100mm+) | 1.4/2 – 3/4 | Big gullets clear heavy chips from large cross-sections |
| Medium solids (25–100mm) | 3/4 – 6/10 | Balance of chip clearance and cut quality |
| Small solids and bar stock | 6/10 – 10/14 | More teeth engaged in smaller material |
| Thin-wall tubing | 8/12 – 14 | Prevents teeth from catching on thin walls |
| Sheet and plate | 10/14 – 18 | Fine pitch for smooth cuts in flat stock |
| Bundles | 3/4 – 4/6 | Must handle multiple walls and air gaps |
The 3-Tooth Rule
Count the thickness of what you're cutting. At least 3 teeth should be in the material at any time. For a 25mm solid round at 4 TPI, that's about 4 teeth engaged — good. At 2 TPI, you'd only have 2 teeth in the cut — too few.
For tubing, measure the wall thickness, not the outside diameter. A 100mm tube with 3mm walls needs fine pitch (10/14 or higher), not the coarse pitch you'd use for a 100mm solid.
Positive Rake vs Neutral Rake
Beyond TPI, tooth geometry matters:
- Positive rake (e.g., 10°) — teeth lean forward into the cut. More aggressive, faster cutting. Best for softer materials and larger cross-sections.
- Neutral rake (0°) — straight tooth face. More controlled cut with less grabbing. Better for harder materials and thin-wall sections.
The Sprint-Plus offers both options across its TPI range, so you can match aggressiveness to your application. The X-FIT uses variable pitch with positive rake for structural steel work.
Still Not Sure?
Blade selection depends on your machine, material, and production needs. Call us at 1 (800) 957-2690 — we'll recommend the right width, TPI, and tooth geometry for your specific application. Every blade is custom welded to your exact loop length at our Hamilton, Ontario facility.