What type of band saw blades are best for aluminum/steel/wood/composites ?

Detailed Breakdown by Material

1. For Aluminum & Other Non-Ferrous Metals (Brass, Copper)

Aluminum is soft but can be gummy, causing chips to weld into the blade’s teeth (called “loading”).

• Best Blade Type: Bi-Metal Blade with M42 Cobalt Teeth.

• Why: The M42 cobalt teeth are hard enough to stay sharp but are specifically good at resisting the high heat and abrasion of aluminum. They are more durable than carbon steel blades.

• Tooth Geometry (Set): Hook Tooth is ideal. It has a deep, aggressive gullet and a positive 10-degree rake angle, which helps pull in large, stringy chips and clear them quickly, preventing loading.

• Tooth Pitch (TPI):

  • 3-6 TPI: For thick solid aluminum (over 4 inches).

  • 6-10 TPI: A great all-around range for bars and structural shapes.

  • 10-14 TPI: For thin-walled tubing and sheet metal to prevent tooth strippage.

2. For Steel & Hard Metals (Stainless Steel, Alloy Steel)

Steel is hard and generates a lot of heat. The blade must be extremely durable.

• Best Blade Type: Bi-Metal Blade with M42 or M51 Cobalt Teeth. This is the industry standard.

• Why: The high-speed steel (HSS) teeth, especially with 8% cobalt (M42), can withstand the high temperatures generated by cutting steel. The flexible spring steel back allows the blade to withstand the tension and cutting forces without breaking.

• Tooth Geometry (Set): Raker Set (every third tooth is unset) is most common. This pattern creates a straighter cut and is excellent for managing the tight, C-shaped chips produced by steel.

• Tooth Pitch (TPI):

  • 8-10 TPI: For large solid sections (4+ inches).

  • 10-14 TPI: The most versatile range for bars, pipes, and structural steel.

  • 18-24 TPI: For thin-walled tubing, sheet metal, and hardened steel to ensure at least 2-3 teeth are in contact with the material.

3. For Wood & Soft Materials

Wood cutting requires a blade that can remove large volumes of material quickly.

• Best Blade Type: Carbon Steel (Flexible Back) or Spring Temper blades.

• Why: These blades are very sharp, inexpensive, and flexible—perfect for the high feed rates and contour cuts common in woodworking. They are not designed for metal’s heat and hardness.

• Tooth Geometry (Set):

  • Hook Tooth: The best choice for most wood cutting. The aggressive 10° rake angle and deep gullet make for fast, efficient cutting in both rip and crosscut directions.

  • Skip Tooth: Has a shallower gullet and is good for cutting softer, more abrasive woods or green wood, as it’s less likely to clog.

• Tooth Pitch (TPI):

  • 2-4 TPI: For massive resawing (slicing thick logs into boards).

  • 3-6 TPI: For general resawing and cutting thick stock.

  • 6-10 TPI: For general-purpose cutting and curves in material up to 2 inches thick.

  • 10-14 TPI: For intricate scroll work and very thin stock.

4. For Composites & Plastics

This category is diverse, so the blade choice depends on the specific material.

• Abrasive Composites (Fiberglass, Carbon Fiber):

  • Best Blade Type: Carbide Grit Edge blades.

  • Why: These blades have no teeth. Instead, they have tungsten carbide granules bonded to the edge. They “grind” through the material, which is ideal for highly abrasive composites that would destroy a toothed blade almost instantly. They produce a clean, chip-free edge.

• Plastics (Acrylic, PVC, Nylon):

  • Best Blade Type: Carbon Steel or Bi-Metal blades with finely set teeth.

  • Why: You need a blade that will make a clean, chip-free cut. Too few teeth will chip the plastic, while a carbide grit blade can melt it.

  • Tooth Geometry (Set): Raker Set or a Wavy Set for very thin plastics.

  • Tooth Pitch (TPI): 10-14 TPI is a good starting point. The goal is to have multiple teeth in contact to shear the plastic cleanly rather than grabbing and cracking it.

Universal Rule: The “3-Tooth Rule”

No matter the material, a crucial rule for selecting TPI is the “3-Tooth Rule.” You should always have at least 3 teeth, but no more than 24, engaged in the workpiece at any time.

• Too Few Teeth (e.g., 3 TPI on thin sheet metal): The teeth can snap off because they take too large of a “bite.”

• Too Many Teeth (e.g., 24 TPI on a thick block): The gullets get packed with chips, causing overheating, poor cutting, and premature blade failure.

In summary:

• Low TPI (3-6): For soft, thick materials (wood, thick aluminum) to remove large chips.

• High TPI (14-24): For hard, thin materials (thin steel, tubing) for a smooth, controlled cut.

• Medium TPI (6-14): Your go-to range for most general-purpose metal and wood cutting.