A reciprocating saw is a handheld power tool that cuts by moving a straight blade rapidly back and forth. It is widely used in construction, demolition, plumbing, electrical work, and emergency rescue because it can cut in tight spaces and through many materials. Unlike a circular saw, it does not need a flat work surface or a long straight path.
Its power, portability, and interchangeable blades make it useful for rough cuts where speed matters more than precision.
Inside the tool, an electric motor turns rotational motion into linear reciprocating motion using a crank, cam, or similar linkage. The blade clamp holds a removable blade, while the shoe or guide plate presses against the workpiece to improve control and reduce vibration. Different blades are chosen for wood, metal, plastic, or masonry based on tooth spacing, length, and material.
Safe use depends on stable footing, proper blade selection, two-handed control, and awareness of hidden wires, pipes, or nails.
Key Facts
- A reciprocating saw cuts using back-and-forth blade motion called reciprocation.
- Cutting speed is often measured in strokes per minute, or SPM.
- Average blade speed can be estimated by v = 2Lf, where L is stroke length and f is strokes per second.
- Power is related to work rate by P = W/t.
- For faster rough cutting, choose a lower TPI blade for wood and a higher TPI blade for metal.
- The shoe or guide plate should stay pressed against the workpiece to improve stability and reduce kickback.
Vocabulary
- Reciprocating motion
- Reciprocating motion is repeated straight-line movement back and forth along the same path.
- Stroke length
- Stroke length is the distance the blade travels in one direction during each cutting stroke.
- SPM
- SPM stands for strokes per minute and describes how many back-and-forth cutting cycles the saw makes each minute.
- Shoe
- The shoe is the flat guide plate near the blade that rests against the material to steady the saw during cutting.
- TPI
- TPI stands for teeth per inch and describes how closely spaced the cutting teeth are on a saw blade.
Common Mistakes to Avoid
- Using the wrong blade for the material is wrong because wood, metal, plastic, and masonry require different tooth designs and blade materials.
- Starting a cut with the shoe floating away from the workpiece is wrong because it increases vibration, reduces control, and can cause the blade to bind.
- Forcing the saw through the cut is wrong because excess pressure can overheat the blade, slow the motor, and make the cut less controlled.
- Cutting into walls without checking for hidden hazards is wrong because electrical wires, water pipes, gas lines, and nails may be behind the surface.
Practice Questions
- 1 A reciprocating saw has a stroke length of 28 mm and runs at 3000 strokes per minute. Estimate the average blade travel speed in meters per second using v = 2Lf.
- 2 A saw does 1800 J of mechanical work while cutting a pipe in 6.0 s. What is the average power output in watts?
- 3 A student needs to cut both a wooden stud with nails and a thin metal pipe. Explain how blade choice and cutting technique should change for each material.