Reciprocating saw

How it works

An electric motor turns a shaft, and a mechanism converts that rotation into straight back-and-forth motion of the blade. The 1952 patent for Milwaukee’s saw describes a crank set at an oblique angle on the rotary shaft. The crank carries an oscillating arm whose spherical head sits in a socket on the blade shaft, and a pair of reduction gears connects the motor to the crank shaft. Milwaukee’s own history says the first Sawzall had only three moving parts.

The blade is a flat strip clamped at one end and free at the other. The tool rests on a shoe at the nose that bears against the work and steadies the cut. Many saws let the shoe slide in and out, which changes how much of the blade shows and where on its length the wear falls.

Many models add orbital action, in which the blade swings slightly forward and back as well as reciprocating. Porter-Cable’s manual says orbital motion is used for fast cutting of wood, while straight reciprocating motion is used for all metal cutting and for wood where finish matters more than speed.

Anatomy

Motor housing and handle: The motor sits behind the gear housing in line with the blade, so the tool is long and narrow; the Ristow and Behlke patent shows the casing, motor, blade shaft and guide plate in one line.
Crank and drive mechanism: Converts motor rotation to blade motion. The 1952 patent uses an oblique crank and an oscillating arm with a ball-and-socket joint.
Blade shaft and clamp: Holds the blade. Current saws use a keyless clamp; Milwaukee’s brochure says its Quik-Lok clamp accepts standard 1/2-inch-shank Sawzall blades and lets the blade be clamped upside down.
Shoe (foot): The plate at the nose that rests on the work. On Porter-Cable’s saws it slides out to limit the depth of cut, and its pivoting form lets the saw cut close to floors and corners. Milwaukee’s 6523-21 has a keyless adjustable shoe and a pivot shoe “for maximum support.”
Variable-speed trigger: Porter-Cable’s manual says the further the trigger is depressed, the higher the speed of the saw.
Orbital selector: Chooses between straight reciprocating and orbital motion on the Porter-Cable PC85TRSO; Milwaukee’s 6523-21 lets the user set the degree of orbital versus straight action.

Variants

Corded saw: The original form; Milwaukee’s October 1952 advertisement lists 2,250 strokes per minute for the first Sawzall.
Cordless saw: JLC’s John Spier says cordless saws have improved to the point that he often leaves his corded saw in the shop, and notes a quick blade-change mechanism on his cordless saw.
Orbital-action saw: Adds a blade path that is not straight; Porter-Cable’s PC85TRSO has dual blade motion, and the 1960 Papworth patent describes a blade moving in a slender modified oval path.
Pivoting-handle compact saw: Milwaukee’s “The Hatchet” has a six-position pivoting handle and, according to the brochure, fits between studs and joists 16 inches on center.
Rotating-handle saw: Milwaukee’s 6523-21 has a 360-degree rotating handle that locks at 45-degree increments, according to its brochure.
Drill attachment: Schmidt’s 1944 application describes an attachment that converts the rotation of a portable electric drill into reciprocating motion.

Specifications

Stroke length · in: Ryobi RJ161V: 1-3/16 in. Milwaukee 6523-21 Super Sawzall: 1-1/4 in. Milwaukee 6524-21 “The Hatchet”: 3/4 in. Only these models have been read.
Strokes per minute, no load · SPM: Ryobi RJ161V: 2,500 maximum. Milwaukee 6523-21 and 6524-21: 0–3,000. Milwaukee’s October 1952 advertisement for the original Sawzall: 2,250.
Blade length · in: JLC’s John Spier says he keeps bi-metal blades of 6, 9 and 12 inches in his truck. No standard length series has been sourced.

Made to

IEC 62841-2-11
EN 62841-2-11

Safety and care

Safety

Wear safety glasses or goggles or a face shield; add hearing protection and respiratory protection where required (CCOHS).
Disconnect the power supply before changing or adjusting the blade (CCOHS).
Secure the workpiece with clamps or a vise, and keep cords clear of the cutting area (CCOHS).
Know what is behind or beneath the material before cutting. Electrical wiring, water pipes, gas lines and HVAC components can be struck (CCOHS). Spier advises looking around to the far side of the work to check.
Hold the saw with both hands. Avoid cutting above shoulder height (CCOHS).
Do not insert or withdraw the blade from a cut while it is moving, and do not put the saw down until the motor has stopped (CCOHS).
Do not use a saw with cracks, missing parts or frayed cords, or a blade with missing teeth (CCOHS).
Never use the saw without its shoe, which Porter-Cable says would cost control, and let the blade extend past the shoe and the thickness of the workpiece, since blade breakage may occur otherwise (Porter-Cable).
Switch the saw on before applying pressure, and place the blade lightly against the work (Porter-Cable).

Care

Keyless blade clamps load up with dust. Spier recommends blowing them out periodically with compressed air and spraying in a lubricant (JLC).
For cordless saws, inspect the battery for damage, cracks or leaks before use, and follow the manufacturer’s instructions for charging and storage (CCOHS).

Tips

Move the shoe out to spread wear along the blade
Spier says extending the adjustable foot in increments brings a fresh part of the blade into use as the teeth wear in metal or other hard material. Porter-Cable’s manual says its shoe slides out to limit the depth of cut and advises using the shortest blade suitable for the thickness of the material.1 2
Keep the shoe against the work
Porter-Cable says holding the shoe firmly against the material stops the saw from jumping or vibrating and minimizes blade breakage. Spier uses the foot to push against the work for the same reason and says it passes the most cutting power to the teeth.1 2
Use orbital action for fast cuts in wood, straight action for metal
Porter-Cable says orbital motion is used for fast cutting of wood, and straight reciprocating motion is used for all metal cutting and for wood where finish is more important than speed. Milwaukee’s Super Sawzall brochure describes its 1-1/4-inch stroke and orbital stroke as being for fastest cutting in thick materials.1 2
Choose the blade by tooth count
Ryobi’s manual gives 10 teeth per inch as typical for wood, 14 for plastics and soft metals and 18 for hard metals. Porter-Cable adds that a finer blade suits ferrous metals and a coarse blade suits nonferrous metals.1 2
Bi-metal blades last longer and can cut nails
Porter-Cable says bi-metal blades, with a carbon steel back welded to high-speed steel teeth, are more flexible and less prone to breaking, which gives longer blade life. Spier uses bi-metal wood or general-purpose blades to cut through nails in old framing, and blades labeled “nail embedded” for the same job.1 2
For a flush cut, turn the blade teeth-up
Porter-Cable says to insert the blade with the teeth facing up and turn the saw upside down to get as close to the work surface as possible; its compact housing and pivoting shoe permit close cutting to floors and corners. Milwaukee’s brochure likewise says blades may be clamped upside down.1 2
Support and lubricate thin metal
Porter-Cable says to clamp wood to the underside of thin sheet metal for a clean cut, and to spread a thin film of oil or coolant ahead of the cut. Ryobi says to sandwich thin sheet between hardboard or plywood, use cutting oil on soft metals and steel, and never use gasoline.1 2
Start an inside cut in a lead hole or by pocketing
CCOHS directs the user to drill a lead hole slightly larger than the blade and insert the blade with the saw off until the shoe rests firmly on the stock. For wood only, Porter-Cable describes a pocket cut: rest the back edge of the shoe on the surface with the moving blade clear of it, then swing the main handle slowly upward so the blade feeds into the material.1 2

History

Earliest documented

1944 (application filed 21 August 1944; patent issued 3 May 1949)

Los Angeles, California

Benjamin F. Schmidt of Los Angeles applied for a patent on an attachment for converting rotary motion to reciprocal motion that could be fitted to a portable electric drive such as a portable electric drill. His stated object was an attachment that would reciprocate a saw, a file, a chipper, a nibbler or a puncher. In one form the tool strokes twice for each revolution of the drive shaft. The patent does not say that the attachment was built or sold. It is the earliest document located in this research, not a proven first.1

The reciprocating saw is a motor with a converter attached. The Schmidt application of 1944 shows the idea in its barest form: a housing that fits the chuck of a portable electric drill and turns its rotation into a stroke, so that a saw, file or other tool can be pushed back and forth. The Ristow and Behlke patent of 1952 puts the same conversion inside a purpose-built casing with the motor at one end and the blade at the other, using an oblique crank and a ball-and-socket arm. Milwaukee says the result had only three moving parts.

The patent states what the tool was for. Its first object is a compact, durable portable cutter that can cut various materials along straight, curved or irregular lines, with a saw blade, file or other cutting tool. It adds that wood, metal or composite material can be cut in any direction, and that a cut can be started inside a flat sheet without drill holes, by a blade with a pointed forward end that pierces the sheet. Milwaukee’s October 1952 advertisement sold the tool as a single-unit, all-purpose power hacksaw, a description that borrows the name of the hand tool.

According to Mental Floss, which relays the Journal of Light Construction’s account, Ristow was looking for a portable powered saw with application in lumber, plumbing and other construction work. Mental Floss adds that few powered saws then in circulation met his criteria, and that a chainsaw would not do for plumbing pipe in a crawl space. Milwaukee’s history says a range of blades let users saw all types of material, and that as residential construction flourished in the United States, Milwaukee power tools became a common sight on job sites.

An orbital blade path is already described in the patent record of the 1950s. Papworth’s 1956 application, granted in 1960, describes a bayonet saw with a simplified mechanism that moves the blade in a slender modified oval path, by direct contact between the plunger and an eccentric, with fewer moving parts than earlier tools. Current manuals describe the feature in simpler terms: Porter-Cable’s manual says orbital motion is used for fast cutting of wood. Whether Papworth’s design reached production, and when commercial saws first offered orbital action, has not been traced.

The tool’s trademarked name has become the general name. The Journal of Light Construction says the manufacturer’s name, Sawzall, has become a generic term, and Mental Floss reports the name as a portmanteau of “saws [it] all.” Spier calls the reciprocating saw one of the first and most versatile power tools a new carpenter is likely to buy, and describes it cutting nails, pipes, bolts and rebar in places a circular saw cannot reach, a wider job than the hacksaw work named in the 1952 advertisement.

Timeline

1944
Benjamin F. Schmidt files an application, issued as US Patent 2,469,277 on 3 May 1949, for a power conversion attachment that reciprocates a saw, file or similar tool from a portable electric drill.1
1951
Milwaukee Electric Tool introduces the Sawzall, which the company calls the first portable electric hacksaw to use a reciprocating mechanism with only three moving parts. The Journal of Light Construction also dates the invention to 1951.1 2
1952
Edward W. Ristow and Versel A. Behlke, assignors to Milwaukee Electric Tool Corporation, file the application (27 June 1952) that issues on 25 February 1958 as US Patent 2,824,455, Portable Reciprocating Saw.1
1952
A Milwaukee advertisement in American Builder for October 1952 presents the Sawzall as a “single unit, all-purpose power hacksaw” with 2,250 strokes per minute, lifetime lubrication and blades for cutting all materials.1
1956
Walter A. Papworth files the application that issues on 22 November 1960 as US Patent 2,961,016, a portable power bayonet saw whose blade moves in a slender modified oval path.1
1958
The Ristow and Behlke patent is granted; its objects include starting a cut within the bounds of a flat sheet without drill holes and keeping all parts that suffer most wear accessible and replaceable.1
1960
The Papworth patent is granted.1

Where the sources disagree

Who invented the Sawzall?

Jerome Schnettler and Edward Ristow, two Milwaukee engineers, with Ristow the chief engineer and Schnettler producing illustrated designs.1 2
Journal of Light Construction, as relayed by Mental Floss
The patent names Edward W. Ristow of Wauwatosa and Versel A. Behlke of Greenfield, Wisconsin, as inventors and Milwaukee Electric Tool Corporation as assignee; Schnettler does not appear.1 2
US Patent 2,824,455 (also noted by Mental Floss)

Was the Sawzall the first reciprocating saw?

It was the first portable electric hacksaw that employed a reciprocating mechanism, with only three moving parts.1
Milwaukee Tool (company history)
Two Milwaukee engineers invented the first reciprocating saw in 1951.1 2
Journal of Light Construction
A patent application of 1944 already describes an attachment that reciprocates a saw or file from a portable electric drill. It does not say that a product was made.1
US Patent 2,469,277 (Schmidt)

Gaps in the record (9)

The 1951 introduction date rests on Milwaukee’s own history and on the Journal of Light Construction, which gives no source. The earliest dated document located is the October 1952 advertisement, and the Ristow and Behlke application was filed in June 1952.
The advertisement text is machine-read from a scan; the weight and stroke length printed in it are not legible enough to quote.
The USPTO trademark record for SAWZALL (first use and registration dates) was not located.
No search was made for hand-held reciprocating saws before 1944, or for patents between Schmidt’s application and Ristow and Behlke’s.
The history of orbital action, the Super Sawzall and cordless reciprocating saws is not sourced beyond the Papworth patent and manufacturers’ manuals.
Whether Schmidt’s attachment was built or sold is not known.
No independent test data has been located, so buying is null.
The standard slugs are guesses at the IEC 62841 series for reciprocating saws and have not been read.
Operating guidance is drawn from three manufacturers’ documents (Porter-Cable 2013, Ryobi undated, Milwaukee brochures), CCOHS and one trade-magazine article; no sawing guide from a neutral standards body was found.