The complete selection guide — from the golden rule to special cases. Get the right teeth per inch for every material and application.
TPI stands for Teeth Per Inch — the number of tooth tips counted in one linear inch of blade length. It is the single most important specification when matching a band saw blade to a workpiece, yet it is also the most frequently mis-selected parameter by both hobbyist and professional users.
TPI determines three critical cutting characteristics:
Selecting the wrong TPI does not just degrade performance — it actively damages the blade and the workpiece. Understanding the principles below will save you time, material, and blade replacements.
The foundational principle of TPI selection is simple: at any given moment during the cut, a minimum of 3 and a maximum of 6 teeth should be in contact with the workpiece.
Fewer than 3 teeth in contact: Each tooth absorbs excessive impact force. This causes tooth chipping, stripped set, and aggressive vibration that degrades cut accuracy and shortens blade life.
More than 6 teeth in contact: Chip clearance becomes insufficient. Sawdust or metal chips pack into the gullets, generating friction heat. The result is premature tooth dulling, workpiece burning, and in severe cases, blade breakage from thermal stress.
To calculate the number of teeth in contact, divide the workpiece thickness (in inches) by the tooth pitch (1/TPI):
Teeth in contact = Workpiece thickness (inches) × TPI
Example: Cutting a 2-inch thick oak board with a 3 TPI blade gives 2 × 3 = 6 teeth in contact. This is at the upper limit of the ideal range — acceptable for hardwood where a finer chip is desirable, but you would not want to go higher.
Use this table as a starting point. The recommended TPI range assumes standard tooth geometry (regular or hook tooth) on a properly tensioned blade:
| Workpiece Thickness | Recommended TPI | Teeth in Contact | Typical Application |
|---|---|---|---|
| < 1/4" (6 mm) | 14–24 TPI | 3–6 | Sheet metal, thin wall tubing, veneer |
| 1/4"–1/2" (6–13 mm) | 10–14 TPI | 3–7 | Thin boards, small stock, scroll work |
| 1/2"–1" (13–25 mm) | 6–10 TPI | 3–10 | General purpose wood and soft metal |
| 1"–3" (25–75 mm) | 3–6 TPI | 3–18 | Hardwood lumber, thick softwood |
| 3"–6" (75–150 mm) | 2–3 TPI | 6–18 | Resawing, thick beam cutting |
| 6"–12" (150–300 mm) | 1–2 TPI | 6–24 | Deep resawing, log milling |
For metal cutting, shift toward the higher end of each TPI range (more teeth) to account for the harder material and need for finer chip control.
TPI alone does not tell the full story. The tooth profile shape significantly affects cutting performance. Four primary tooth types are used in band saw blades:
The standard tooth form with a zero-degree rake angle (the tooth face is perpendicular to the blade direction). Regular teeth produce a controlled, consistent cut with good surface finish. They are the default choice for general-purpose cutting of wood, plastic, and non-ferrous metals.
Best for: Thin stock, finish cuts, non-ferrous metals, plastics.
Hook teeth have a 10-degree positive rake angle, meaning the tooth face leans forward into the cut. This aggressive geometry pulls the blade into the workpiece, increasing the feed rate and chip size. The larger gullet volume compared to regular teeth improves chip evacuation in thick material.
Best for: Thick hardwood, fast ripping, production cutting where speed matters more than surface finish.
Skip teeth have the same zero-degree rake as regular teeth, but with every other tooth removed — effectively halving the TPI while doubling the gullet space. This design maximizes chip clearance in soft, gummy, or resinous materials that tend to pack gullets.
Best for: Softwood, green (wet) wood, foam, rubber, and other materials that produce long, stringy chips.
Variable pitch blades alternate between two different tooth spacings (e.g., 2/3 TPI or 4/6 TPI). The varying pitch disrupts harmonic vibration that causes blade "singing" and washboard patterns on the cut surface. Variable pitch also reduces noise levels significantly.
Best for: Structural steel, pipe and tube (varying wall engagement), any application where vibration or noise is a concern.
| Tooth Type | Rake Angle | Gullet Size | Cut Speed | Finish Quality | Best Material |
|---|---|---|---|---|---|
| Regular | 0° | Standard | Moderate | Smooth | Thin stock, non-ferrous |
| Hook | +10° | Large | Fast | Moderate | Thick hardwood, production |
| Skip | 0° | Extra large | Moderate | Rough | Softwood, foam, rubber |
| Variable | 0–10° | Alternating | Moderate | Smooth | Metal, structural, tube |
Using a 10 TPI blade to cut 4-inch hardwood puts 40 teeth in contact with the workpiece simultaneously. The gullets cannot possibly clear that volume of sawdust. The chips re-cut and compact, generating extreme friction heat. Symptoms: burn marks on the cut face, blade runs hot to the touch, rapid tooth dulling, and a distinctive "cooking" smell from the workpiece.
Fix: Drop to 2–3 TPI with hook teeth. Reduce feed pressure and let the blade cut at its natural rate.
Using a 3 TPI blade to cut 1/4-inch aluminum plate puts less than 1 tooth in contact at any time. Each tooth takes a massive impact bite, causing the blade to grab and stall, teeth to strip or chip, and the workpiece to vibrate violently. The cut will be rough and potentially dangerous.
Fix: Switch to 14–18 TPI with regular tooth geometry. Ensure the blade is properly tensioned to prevent deflection.
Two blades can have identical TPI but perform completely differently based on tooth geometry. A 3 TPI regular tooth blade will cut slowly and leave a clean surface in thick pine. A 3 TPI hook tooth blade will rip through the same material 30–40% faster but with a rougher finish. Selecting TPI without considering tooth type leaves performance on the table.
The "universal blade" does not exist. A blade optimized for resawing 8-inch walnut (2 TPI, hook tooth, 3/4" wide) will perform terribly at cutting curves in 1/2-inch plywood (needs 10 TPI, regular tooth, 1/4" wide). Keeping 2–3 blades on hand for different jobs is not a luxury — it is a fundamental requirement for good results.
Resawing — slicing a board through its width to produce thinner boards — is the most demanding band saw operation. The blade must cut through the maximum possible material thickness while maintaining a straight, consistent cut. Use the widest blade your saw accepts, 2–3 TPI hook tooth, and proper blade tension (15,000–20,000 PSI for carbon steel). Feed slowly and let the blade do the work.
Tight curves require narrow blades (1/8"–1/4" wide) with higher TPI. The narrow blade can navigate tight radii, and the higher TPI compensates for the thin workpiece typically encountered in scroll and pattern work. A 1/4" blade at 6 TPI can cut curves down to approximately 5/8" radius.
Frozen meat, fish, and other food products behave like hard, brittle materials. Use 4–6 TPI with hook teeth for efficient chip removal. Stainless steel blades or food-grade carbon steel blades are required for sanitation compliance. Keep blade speed moderate (2,000–3,000 FPM) to prevent surface thawing.
Metal cutting requires high TPI to distribute the cutting force across multiple teeth and produce controlled metal chips. For structural steel and solid bar, 4–6 TPI bi-metal blades are used on horizontal saws. For thin-wall tubing and sheet, 14–24 TPI prevents the "straddling" effect where a tooth catches on the thin wall and strips.
TPI selection does not happen in isolation. It is part of a three-variable system:
The general relationship: as blade width increases, TPI should decrease and gauge can increase. A wide resaw blade (3/4"–1") will be 2–3 TPI at 0.025"–0.032" gauge. A narrow scroll blade (1/8"–1/4") will be 10–14 TPI at 0.014"–0.020" gauge.
| Blade Width | Typical TPI | Typical Gauge | Min Curve Radius | Primary Use |
|---|---|---|---|---|
| 1/8" (3 mm) | 14–24 | 0.014" | 1/8" | Tight scroll work |
| 1/4" (6 mm) | 6–14 | 0.020" | 5/8" | Curves and general cutting |
| 3/8" (10 mm) | 4–10 | 0.025" | 1.5" | General purpose |
| 1/2" (13 mm) | 3–6 | 0.025" | 2.5" | All-round, light resaw |
| 3/4" (19 mm) | 2–3 | 0.032" | 5" | Resawing |
| 1" (25 mm) | 1–3 | 0.035" | 7" | Deep resawing, beam |
Not sure which TPI to choose? Our interactive TPI calculator takes your workpiece material and thickness, then recommends the optimal TPI range and tooth type for your specific application.
TPI selection is only half the equation — the steel grade determines blade life. For general woodworking, 75Cr1 (DIN 1.2003) offers the best balance of wear resistance and cost. For hardwoods, SK85 provides HRC 60+ edge retention. If you're cutting metal, 75Ni8 bi-metal backing is the industry standard. Read our 75Cr1 vs 65Mn comparison for a detailed material selection guide, or use the Grade Cross-Reference Tool to find the right grade for your market.
We supply heat-treated band saw blade strip in 75Cr1, SK5, SK85, and 65Mn — and can tooth-cut to your specified TPI, tooth type, and set pattern. From raw strip to finished blade-ready product, one source.