What Is a Reciprocating Saw?
A reciprocating saw (or Sawzall) is an electrical cutting tool that is used to cut drywall, metals, plaster, tubing, wood, and wood lath. It is used most heavily in the construction, electrical, and plumbing trades; but it is also a handy tool to have in the home repairman’s arsenal.
Reciprocating saws move the blade to and fro rather than rotating it. Their speed is measured in SPM (strokes per minute). A variable-speed reciprocating saw will have a minimum speed and a maximum speed, such as 1700/2700 SPM. The harder you squeeze the variable speed trigger, the faster the blade moves. It is recommended that when using a variable speed saw, you allow the blade to attain its maximum speed before cutting. Your saw could be damaged by prolonged use at very slow speeds. A stroke length of one and one-eighth inches is the standard and refers to the distance the blade travels in one forward cutting stroke.
Several new models of reciprocating saws boast tool-free blade changing, a nice feature that eliminates the need to use an Allen wrench or screwdriver when you need to change a blade. Some models have an electric brake, which stops the blade immediately if you release the trigger. For professional jobs, where a reciprocating saw is being used for repetitive work, a switch lock can be engaged so that the saw will run continuously.
Below are a few common terms you will encounter in relation to your reciprocating saw. Refer to your owner’s manual for diagrams that will identify the parts of the saw for you.
Adjustable Shoe the shoe is on a pivot, which allows it to turn when you work on beveled or slanted wood so that the cut will go completely through without splintering the wood.
External brush access – this feature is intended for work on materials such as aluminum siding, as it reverses the blade to smooth the cut.
Pocket Cutting cutting a hole in a finished wall.
Blade Clamping installing a blade into the saw. Ensure that the unit is turned off, and unplugged before you begin. First, you loosen the set screw with an Allen wrench or screwdriver. Then, between the reciprocating shaft and the blade clamp, insert the blade shank from the front. Place the hole in the blade over the pin on the reciprocating shaft and tighten the set screw. If a blade breaks and you can’t get the shank out of the clamp, loosen the set screw and pry the shank out with a pointed object, such as a nail.
A relatively recent improvement in blade changing is the blade clamp release lever, which permits you to change blades without having to use an allen wrench or screwdriver. Always be sure the unit is turned off, and then unplug it before doing the following:
- Pull up on the blade clamp release lever.
- Insert the blade shank from the front.
- Push down on the blade clamp release lever.
To remove the blade from the saw with this new process:
- Open the blade clamp release lever.
- Remove the blade.
Horizontal Blade Positioning
When you need to cut close to ceilings, floors, or walls where you have limited clearance, you can install the blade in the horizontal position. To avoid kickback, make sure that the blade guard is pressed against the framing.
You can cut in difficult areas, such as floors and corners. Before cutting into any area where the saw might encounter live electrical wiring, please review the safety tips for proper handling of the tool, and remember always to wear eye protection.
An assortment of blades is available for the different types of metal that you may want to cut. Ferrous metals (those containing iron) require a finer blade. Non-ferrous metals need a coarser blade. If you’re working with thin gauge sheet metal, it’s beneficial to clamp wood to either side of the sheet to ensure a clean cut without tearing the metal. Never force the cutting, as this will shorten the blade’s life. For longer blade life and ease of operation when cutting metal, spread a thin film of oil or another coolant along the line ahead of the saw cut.
Anchor the piece of wood you’re going to cut and hold the saw firmly with both hands. Place the blade lightly against the wood. Before applying pressure to the wood, switch on the saw, and allow it to obtain its maximum speed. To avoid breaking the blade and stop the saw from jumping and vibrating, hold the shoe firmly against the wood.
A final note on blade types: Generally speaking, use a fine-tooth for metals, coarse for rough-cut wood, and a fine-tooth for a cleaner cut on woods. If you use the wrong blade, you can put burn marks on your workpiece.
Important Safety Tips
Before operating your reciprocating saw, take a few minutes to read the owner’s manual. Familiarize yourself with hazards and recommended operational procedures.
Do not remove the blade guard with which your unit is equipped.
Hold the saw only by the provided gripping areas. Grabbing it by the front metal parts can result in electrical shock if you accidentally cut into live electrical wires when sawing into walls or floors.
If the handle of the unit is cracked or broken, don’t use it. Electrical shock could occur if you touched anything metal that is grounded.
Do not use if you or the reciprocal saw are wet or while standing on a damp or wet surface.
Always wear safety glasses.
Keep children and pets away from all power tools.
Protect the cord. Keep it away from heat, and don’t yank on it to disconnect it from an outlet.
If you must use an extension cord, verify that it is heavy enough to carry the current your reciprocating saw will use. This information is contained within the specifications section of your owner’s manual. A smaller gauge number indicates a heavier cord. If you’re using your reciprocating saw outside, make sure your extension cord is approved for outdoor use. They will be marked with a suffix of W-A. Replace extension cords at any sign of damage; inspect frequently.
Use clamps to hold pieces of work stationary.
Ensure that you have stable, secure footing.
When not in use, disconnect from power source.
Ensure the switch is turned off before you turn the tool on. Don’t carry it with your finger on the switch trigger.
Press the shoe firmly against the material that you’re cutting, especially if it’s something hard like metal. If you don’t, the blade will catch in the workpiece, and you will find yourself reciprocating instead of the saw blade.
Keep your hands away. Do not reach under your work while the blade is moving.
As with all motors, operate away from fumes, gases, and flammable liquids.
Do not use the unit if the cord shows any sign of damage. Maintain a safe distance at all times between the cord and the machine when you’re operating it.
Do not use strong solvents, brake fluids, gasoline, or petroleum-based products to clean your reciprocating saw. Using a clean cloth when cleaning will keep the handles dry and avoid a buildup of grease and oil.
Use only the blades specified to be used with your unit.
An old saying goes: Measure twice, cut once. When working with a reciprocating saw, you might want to add a few words: Think thrice, measure twice, and cut once. Have fun.An old saying goes