Reciprocating saws are one of the most versatile tools available. Part of that versatility comes from the vast array of blades available for cutting through a wide range of materials. With the right blade, your sawzall can cut through wood, nails, fiberglass, branches, plaster, masonry, and metals including aluminum, cast iron, steel, and even high-strength alloys. But how do you choose the proper blade for the material you need to cut?
There are many blade characteristics to consider. In general, this includes the blade material, length, width, thickness, and teeth-per-inch (TPI). For specific cut types, blade shape, tooth shape, kerf-width, gullet, and tooth pattern can be selected. Even though there are many options, choosing the right reciprocating saw blade is easy once you know the basics.
- The number of teeth per inch (TPI), along with gullet size, width and depth of the space between the teeth, determines the material the blade can cut.
- Blades with a low TPI deliver faster cuts with rougher edges and are ideal for cutting wood.
- Blades with a high TPI deliver smooth, slow cuts and are the best reciprocating saw blades for metal.
- The number of TPI ranges from three to 24.
- Try to have at least three teeth come in contact with the material at all times to reduce snagging.
Composition and Uses
Many new users wonder if reciprocating saw blades are universal. While some multipurpose reciprocating saw blades can handle a few types of jobs, most tasks require a dedicated blade type.
There are different types of reciprocating saw blades on the market today. Choosing the right one is essential. Most reciprocating saw blades are made of carbon steel, high-speed steel, bi-metal or carbide grit. Here's what you should know about the different reciprocating saw blade types:
- Carbon steel blades are flexible to allow bending without breaking and are great for cutting wood or plastic. Carbon steel blades are generally the best reciprocating saw blades for trees.
- High-speed steel blades have durable teeth but are more prone to breakage and last up to five times longer than high-carbon steel.
- Bi-metal blades are combined high-speed steel teeth for longevity and heat resistance, with a carbon-steel body for flexibility and break-resistance, and last up to 10 times longer than high-carbon steel. A bi-metal blade can be the best reciprocating saw blade for wood, particularly if you're working with smaller pieces for woodworking projects and not cutting large tree trunks. Wood cutting reciprocating saw blades range from 14 to 24 TPI.
- Carbide-grit blades are used for materials such as fiberglass, ceramic tile and cement board.
Using The Wrong Blade: What Happens
As each blade is designed for a specific application, it’s best you use this solely for that application, interchanging between blades when necessary.
Using the incorrect blade can have many consequences, which primarily include damage to your blade. Blades can bend, often becoming broken when used at the wrong speed and on the wrong material.
This not only damages your blade and also your reciprocating saw itself, but it can also cause an accident which could prove fatal.
This is also can add up to create an expensive replacement, as many blades designed for specific applications, such as masonry and nail embedded wooden blades, are often expensive.
High Carbon Steel (HCS)
Carbon steel blades are the most inexpensive type, and also the most common. They are the softest of the blade materials and tend to be more flexible to allow bending without breaking in the proper application. That also makes them the least durable. They are good for cutting softer wood, particle board, and plastics. However, they quickly become dull when used on hard woods, metal, and other hard materials.
High Speed Steel (HSS)
High-speed steel blades are subjected to a tempering process that makes them more heat-resistant and durable than their carbon steel counterparts. They last up to 5 times longer than carbon steel. That hardness makes them less flexible and thus more prone to breaking when bent. It also allows them to cut hardwoods, aluminum, and non-ferrous metal without excessive wear, dulling, and tooth breakage.
Bi-metal blades combine a high-carbon steel body for flexibility and break-resistance, and high-speed steel teeth for heat-resistance, hardness, and durability. On average, Bi-metal recip blades will last 10 times longer than a carbon steel blade. While the cost slightly more than HSS or HCS blades, they offer the versatility and toughness for more demanding applications. This makes them the most popular blade type among people in the trades, auto yards, and other professions where sawzalls see frequent or daily use. We also recommend bi-metal blades for DIY projects and occasional use because of their durability and long life.
Carbide tipped sawzall blades are also bi-metal blades, but with a carbide (tungsten carbide or titanium carbide) tip at the end of each tooth. These carbide materials are extremely hard, heat-resistant, and impact-resistant. They also offer 20 times the cutting life of a standard bi-metal blade. The can cut thicker pieces of metal including cast iron, stainless steel, and high-strength alloys. This makes them ideal for cutting metals that would almost immediately destroy a HCS, HSS, or traditional bi-metal blade, such as grade 8 bolts and boron reinforced auto pillars.
Diamond blades are also abrasive, but use diamonds instead of carbide. These are the most expensive reciprocating saw blades. They are used to cut concrete, glass, fiberglass, and ceramic, and can also cut fiber cement, cast iron, and masonry. The hardness of diamonds and fineness of the abrasive grit is necessary to cut brittle material like glass (that would be destroyed by a toothed blade) and very hard and dense material like concrete (that would destroy a toothed blade). Due to the hardness of diamonds, diamond grit blades have a much faster cut than carbide grit and last 5 to 20 times longer.