Match the blade to the material
A reciprocating saw cuts whatever you point it at, and that range is exactly why blade choice matters. A blade that slices green lumber in seconds can be ruined by a single nail, and a thin metal-cutting blade can snap in a rough wood cut. This article explains the three things to compare: material, length and teeth per inch (TPI). It names no brands and ranks nothing.
Blade material
- High-carbon steel blades are flexible and inexpensive, and are typically used for wood. They dull quickly and are not meant for metal.
- Bi-metal blades pair a flexible spring-steel body with a harder cutting edge, often high-speed steel. They tolerate nails and thin metal better and are a common all-around choice for mixed demolition.
- Carbide-tipped or carbide-grit blades last the longest in abrasive or hard materials such as cast iron, plaster, tile or heavy stainless, but they usually cost more and may behave differently in softwood. Always check the packaging for the intended material.
Blade life depends on how you use it. Heat is the enemy, so cutting too fast, applying heavy pressure or running a dull blade shortens life much more than people expect.
Blade length
Blade length determines how deep you can cut and how stable the blade feels.
- Short blades (around 4 to 6 inches) are stiffer and suit pipe, trim and thin stock where little reach is needed.
- Medium blades (around 6 to 9 inches) cover most general-purpose work.
- Long blades (around 9 to 12 inches) reach through thick lumber or deep cuts, such as a post or an older framing member. They also flex more, which can cause wandering or buckling when pushed hard.
A useful rule is to choose a blade long enough that the cut does not use the last teeth near the tool. Using only a small part of the blade wears that section faster, so move the shoe in or out occasionally to spread the wear. Reciprocating saw features such as stroke length and orbital action also affect how quickly a blade cuts and wears.
Teeth per inch
TPI is a trade-off between speed and smoothness.
| TPI range (approximate) | Typical use |
|---|---|
| Roughly 3 to 6 | Fast, rough cuts in green or wet wood, pruning, thick timber |
| Roughly 6 to 10 | General wood and nail-embedded lumber, mixed demolition |
| Roughly 10 to 18 | Metal pipe, conduit, sheet and thicker metal |
| Roughly 18 to 24 | Thin metal, tubing and sheet, where several teeth must touch the work |
These ranges vary between makers and should be taken as a guide. For metal, a general principle is to keep multiple teeth in contact with the work so that thin material does not catch and tear the blade. For wood, coarse teeth clear sawdust faster and cut quicker. A higher TPI in thick wood tends to clog and burn.
Tooth shape and blade width
Some blades use a progressive or variable tooth pattern, with a mix of tooth sizes to handle changing material, which helps for demolition where you might hit wood, a nail and metal in one pass. Wider, thicker blades resist bending and are good for heavy demolition, while thin, narrow blades turn better for scrolling and for plunge cuts, where the blade tip enters the middle of a surface. Blades marketed for pruning have large, aggressive teeth and are meant for live wood rather than lumber.
Common job pairings
- Tear-out of framing with nails: a bi-metal blade with a medium TPI and enough length for the stud depth.
- Cutting a pipe or conduit: this is a case of cutting metal with a power saw, so use a finer-tooth metal blade, a clamped workpiece and slow speed.
- Rough cutting green branches or rough timber: a coarse, wood-focused blade.
- Cutting plaster or masonry-like materials: a blade rated for that material, with appropriate dust protection. Never assume a general blade can cut it.
Safety notes
Always unplug the saw or remove the battery when changing a blade, and let used blades cool. Edges are sharp, and a blade can bind and kick. Keep both hands on the saw, rest the shoe against the work for stability, and let the blade reach full speed before it contacts the material. Wear eye, hearing and dust protection, and be aware of hidden electrical wires, pipes and gas lines in walls, which are a serious hazard whenever you use demolition tools, so check before cutting and shut off the circuits you are working near. Avoid cutting materials that might contain asbestos or lead paint without proper guidance from a qualified professional; the real question there is not blade choice but safe handling.
Getting more life from a blade
Support the work so it does not vibrate, use a steady push instead of leaning hard, and avoid twisting the blade in the cut. Stop and replace a blade that has lost teeth or begins to burn, since a dull blade makes the saw vibrate more and work harder. Keeping a few types on hand, such as a coarse wood blade, a general demolition blade and a fine metal blade, is usually more economical than trying to make one blade do everything.