This table shows the recommended TPI range for common material thicknesses, based on the golden rule of maintaining 3-6 teeth in contact with the workpiece at all times.
| Material Thickness | Inches | Wood TPI | Metal TPI | Teeth in Contact |
|---|---|---|---|---|
| Very thin | < 1/4" | 14–18 | 18–24 | 3–6 |
| Thin | 1/4" – 1/2" | 10–14 | 14–18 | 3–6 |
| Medium | 1/2" – 1" | 6–10 | 10–14 | 3–6 |
| Thick | 1" – 2" | 3–6 | 8–10 | 3–6 |
| Very thick | 2" – 4" | 2–4 | 6–8 | 3–6 |
| Extra thick | 4" – 8" | 1.5–3 | 4–6 | 3–6 |
| Maximum | > 8" | 1–2 | 3–4 | 3+ |
A blade that is too thick for the wheel radius will fatigue and crack prematurely. The safe ratio is R/t ≥ 500 (wheel radius divided by blade thickness ≥ 500). Some sources use R/t ≥ 1000 for maximum life.
| Wheel Diameter | Wheel Radius | Max Thickness (R/t=500) | Recommended Thickness | Typical Saw Class |
|---|---|---|---|---|
| 9" | 4.5" | 0.009" (0.23 mm) | 0.014" (0.35 mm)* | Benchtop |
| 10" | 5" | 0.010" (0.25 mm) | 0.014" (0.35 mm)* | Benchtop |
| 12" | 6" | 0.012" (0.30 mm) | 0.020" (0.50 mm)* | Small workshop |
| 14" | 7" | 0.014" (0.36 mm) | 0.025" (0.64 mm) | Standard workshop |
| 18" | 9" | 0.018" (0.46 mm) | 0.025"–0.032" | Mid-size |
| 20" | 10" | 0.020" (0.51 mm) | 0.032" (0.81 mm) | Large |
| 24" | 12" | 0.024" (0.61 mm) | 0.035" (0.89 mm) | Industrial |
| 30" | 15" | 0.030" (0.76 mm) | 0.042" (1.07 mm) | Industrial |
| 36"+ | 18"+ | 0.036" (0.91 mm) | 0.050" (1.27 mm) | Heavy industrial |
* Small benchtop saws commonly use 0.014"–0.020" blades despite exceeding the strict R/t=500 rule, because blade speeds are lower and cut pressures are minimal. Blade life will be shorter.
Narrower blades can cut tighter curves. If you need to cut curves, choose the narrowest blade that still provides adequate beam strength for your material.
| Blade Width | Min. Cutting Radius | Best For |
|---|---|---|
| 1/8" (3 mm) | 1/4" (6 mm) | Tight scrollwork, intricate curves |
| 3/16" (5 mm) | 3/8" (10 mm) | Small curves, detailed work |
| 1/4" (6 mm) | 5/8" (16 mm) | General curves, circles |
| 3/8" (10 mm) | 1.5" (38 mm) | Gentle curves, medium radii |
| 1/2" (13 mm) | 2.5" (64 mm) | General purpose, mild curves |
| 3/4" (19 mm) | 5" (127 mm) | Resawing, gentle curves |
| 1" (25 mm) | 7" (178 mm) | Resawing, straight cuts |
| 1.5" (38 mm) | — | Heavy resawing only |
At any moment during cutting, there should be a minimum of 3 teeth and ideally no more than 6 teeth engaged in the material.
Why minimum 3? With fewer than 3 teeth in the cut, each tooth takes excessive load. The blade will "straddle" the material — teeth will straddle the workpiece edges, causing the tooth tips to catch and strip. This leads to tooth breakage, rough cuts, and excessive vibration.
Why maximum 6? With too many teeth in contact, the gullets (the spaces between teeth) fill up with chips. Packed gullets mean chips can't clear, causing heat buildup, blade wandering, and premature dulling. The blade essentially "clogs" like a saw cutting too fast.
The formula:
Teeth in Contact = Material Thickness (inches) × TPI
For example: cutting 1.5" thick oak with a 4 TPI blade gives you 1.5 × 4 = 6 teeth in contact — right at the upper limit of the ideal range.
The tooth form affects cutting speed, surface finish, and chip clearance. Choose based on your material and cutting goal.
Shape: 0° rake angle, rounded gullet
Best for: Thin materials, fine finishes, metal cutting
Why: Smallest gullet — good for materials that produce small chips. The 0° rake gives a scraping action that produces smooth surfaces but cuts slower.
Shape: 10° positive rake angle, deeper gullet
Best for: Hardwood, thick wood, aggressive cutting
Why: The positive rake angle pulls the blade into the work, giving a faster, more aggressive cut. Larger gullets clear chips better in thick material.
Shape: 0° rake angle, wide-spaced teeth (every other tooth removed)
Best for: Softwood, green wood, foam, rubber, non-ferrous metals
Why: Extra-large gullets prevent clogging in gummy or soft materials. The wide spacing also reduces heat. Common on 3 TPI blades for resawing.
Shape: Alternating tooth spacing (e.g., 2/3 TPI, 4/6 TPI)
Best for: Metal cutting, vibration reduction, mixed materials
Why: Different tooth spacings break up harmonic vibration, producing quieter cuts with less chatter. Essential for cutting metal sections and tubing.
For resawing (cutting boards to thinner slabs), use 2-4 TPI with a wide blade (1/2" to 3/4" or wider). The low TPI provides large gullets to clear the massive amount of sawdust produced. A skip or hook tooth pattern works best. For a 14" band saw, a 1/2" × 3 TPI skip tooth blade is the most popular resawing setup.
Generally no. Wood blades have larger teeth and wider gullets optimized for clearing wood chips. Metal-cutting blades need higher TPI (14-24) with finer teeth. If you must cut both, a bi-metal blade with variable pitch (e.g., 8/12 TPI) can handle light metal and wood, but won't excel at either.
Blade drift is usually caused by: (1) dull teeth on one side, (2) incorrect blade tension — carbon steel should be tensioned to 15,000-20,000 PSI, (3) misaligned guides, or (4) too few teeth in the cut (use higher TPI). For resawing, make sure you're using a wide blade with proper set.
Factory-direct precision strip in 13 steel grades. Heat treated to your hardness spec.