How to Choose Reciprocating Saw Blades: Bi-Metal vs. Carbon Steel vs. Carbide
Quick Answer: Choose carbon steel blades for clean wood and plastic, bi-metal blades for wood with nails, metal pipe, and general-purpose cutting, and carbide blades for brick, tile, cast iron, and abrasive materials. For TPI, use fewer teeth for thick materials and more teeth for thin materials. If you only buy one type, buy bi-metal.
What Is the Difference Between Bi-Metal, Carbon Steel, and Carbide Blades?
The three blade materials differ in one core way: tooth hardness and durability.
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Carbon steel blades are the cheapest option. They cut clean wood, plastic, and soft materials well, but dull quickly on nails, hard wood, or metal.
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Bi-metal blades combine a spring steel body with high-speed steel teeth. They last 2–10 times longer than carbon steel and can cut wood with nails, metal pipe, angle iron, and bolts.
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Carbide blades have tungsten carbide teeth. They cut cast iron, brick, tile, cement board, and fiberglass, but are brittle and chip easily on nails.
Summary: Carbon steel for wood, bi-metal for general use, carbide for masonry and abrasive materials.
What TPI Should You Use for a Reciprocating Saw?
TPI stands for teeth per inch. Lower TPI means larger teeth, faster cuts, and rougher edges. Higher TPI means smaller teeth, slower cuts, and cleaner edges.
Rule of thumb: The thinner the material, the higher the TPI. Always keep at least 2–3 teeth in contact with the material to prevent snagging or breaking.
Reciprocating Saw Blade Selection Chart (By Material)
| Material | Recommended TPI | Blade Type | Key Note |
|---|---|---|---|
| Wood (rough/fast cuts) | 3–6 | Carbon steel or bi-metal | Wet wood may pinch the blade |
| Wood with nails/pallets | 6–10 | Bi-metal | Carbon steel will chip |
| PVC/PPR pipe | 14–24 | Carbon steel or bi-metal | Medium-low speed to prevent melting |
| Thick metal pipe/angle iron | 10–14 | Bi-metal | Use cutting fluid |
| Thin sheet metal/thin pipe | 18–24 | Bi-metal | Fine teeth prevent snagging |
| Brick/tile/cast iron | Carbide grit | Carbide | Do not use on nails |
How Long Should a Reciprocating Saw Blade Be?
Choose blade length based on material thickness. A common rule is: material width + 50 mm = minimum blade length. For example, cutting an 80 mm pipe requires a blade of at least 130 mm.
What Blades Should You Buy First?
Do not expect one blade to cut everything. The most practical starter set is:
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One bi-metal general-purpose blade (10–14 TPI)
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One fine-tooth metal blade (18–24 TPI)
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One coarse wood blade (6 TPI)
This three-blade set covers about 90% of everyday cutting tasks.
Frequently Asked Questions
What is the best reciprocating saw blade for cutting wood with nails?
A bi-metal blade with 6–10 TPI. Carbon steel will dull or chip on nails.
What blade cuts both wood and metal?
A bi-metal blade with 10–14 TPI can cut both, but it is not ideal for thick stock or high-volume cutting.
Can a reciprocating saw cut brick or tile?
Yes, but only with a carbide grit blade. Bi-metal and carbon steel blades will not work on masonry.
What TPI is best for cutting metal pipe?
Use 10–14 TPI for thick-wall pipe and 18–24 TPI for thin-wall pipe. Always use cutting fluid.
How do I keep my reciprocating saw blade from breaking?
Keep at least 2–3 teeth in contact with the material, match the blade to the material, and avoid forcing the cut.
Bottom Line
Carbon steel cuts wood. Bi-metal cuts almost everything. Carbide cuts masonry. Choose TPI by material thickness—thicker material, fewer teeth; thinner material, more teeth. If you want a simple setup, buy one bi-metal blade, one fine-tooth metal blade, and one coarse wood blade. That covers most jobs.
