Conduit and Wire Cutters
Published: September 2002
In an ideal world with perfectly sized buildings, conduit would install in standard lengths. Life and architectural design being what they are, answering to other needs and specifications, a great deal of conduit—steel, aluminum, or plastic—requires cutting. And because cable and large-gauge wire that run inside conduit often come on rolls or in approximate lengths, those materials also require cutting on the job, to fit exactly from panel to panel or splice box to panel. Specialized tools often speed both tasks.
There are many tools that can cut conduit, including hacksaws, portable band saws, cut-off machines, metal-cutting circular saws and pipe cutters. Some conduit cutting tools are also useful for cutting angle iron, round, square or rectangular metal profiles, threaded rod and unistrut, and for cutting other conduit supports, equipment supports and frames.
The relatively lightweight Porter Cable 7724 Big Capacity Variable-Speed Porta-Band Saw ($275) cuts 41/2-inch x 43/4-inch and 43/4-inch round conduit. The 14-pound 6-amp, AC unit, which has 100 percent ball and needle bearings and spur gear and chain drive, features a variable-speed dial with 100-245 SFPM range. The saw, which comes with an 18T bimetal blade, can mount on a stand for production without fatigue and more accurate cutting. An accessory portable vise acts as a jig for applications that require cutting pipe in place.
Portable band saw blades have a variety of tooth pitches (distance from tip of one tooth to tip of the next) to accommodate differences of materials being cut. Popular tpi (teeth per inch) for cutting electrical conduit include 24 (for thin wall conduit), 18 and 14/18.
Lenox Tools offers two lines of portable band saw blades, with standard length of 44 7/8-inch and 1/2-inch width. The Wolf-Band Portable Band Saw Blade, at 0.02-inch thickness, is available in 18 and 14/18 tpi, for conduit with a 1/16-inch and larger thickness, and in10/14, 14, and 24 tpi. The Master-Band Premium blades are available at 0.023-inch width in the same five different teeth configurations.
Metal cutting/dry cutting saws
Metal cutting saws work fast (generally five-10 seconds per cut) and clean. Typically, a carbide tip blade may average about 3,000-5,000 cuts per blade, with sharpening. All dry-cut metal blades are fairly similar and are not designed for superfine work (When you need an extremely fine cut, a band saw is the way to go.)
In addition to cutting conduit efficiently, the DeWalt, Hitachi, and Makita saws, below, are all also suitable for cutting soft-steel conduit and pipe, soft-shaped steel, angled steel, channel steel, round bars and threaded rod.
DeWalt DW872 Heavy-Duty 14-inch Multi-Cutter Saw (about $450), for cutting up to 5 3/16-inch round conduit and 6 1/2-inch x 4 1/2-inch rectangular shapes, comes on a wide, heavy-duty base with a quick-lock vise for maximum stability. Other features of the 4-hp 47-pound tool, which runs at a 1,300-rpm no-load speed, include an ergonomically designed handle and a quick-retracting guard. The 70-tooth carbide-tipped metal blade maintains a consistent depth of cut and lasts substantially longer than abrasive blades, while generating considerably less dust. The blade, with a standard 1-inch round arbor, provides a clean, accurate, burr-free finish.
Hitachi CD14F 14-inch ($388-$450) Portable, Dry-Cutting Metal Saw, for cutting up to 5 1/8-inch round conduit, 5-inch square and 5-inch x 6-inch flat shapes, comes on a stand with a heavy-duty quick-locking vise, and sports a 2.5-hp motor and an 80-tooth carbide blade. A chip collection compartment aids efficient cleaning and a spindle lock facilitates quick blade changes. Other features include a safety cover that protects the operator from sparks, a switch that guards against current overload, and a carrying handle.
Makita LC1230 12-inch ($429) Metal Cutting Saw features a 15-amp motor and a 12-inch carbide-tipped blade that cuts up to 4 1/2-inch conduit at 90 degrees virtually burr and spark free. The tool, which comes on a large cast-aluminum base for stability and weighs about 42 pounds, has a quick release vise, a shaving collection tray, externally accessible brushes, and a large D-handle, for easy gripping, with a two-finger trigger and a lock-off button.
Dry-cut metal saws can use carbide-tipped toothed blades. Though carbide-tipped steel blades cost more than standard abrasive blades, they last up to 50 times longer (making cost per cut a lot less), cut about four times faster, and do not generate the sparks or dust that abrasive blades do. In addition, they leave burr-free edges after cutting, and keep the conduit cool to the touch. Metal cutting blades should not be used in compound miter saws because the blade teeth could fly off at the higher speed. (A miter saw operates at about 3,400-4,900 rpm while a dry cut metal saw is designed to work at a much slower 1,300 rpm.)
Metal-cutting circular saws
Metal-cutting circular saws are another option for cutting conduit and miscellaneous metal shapes. Though there are dedicated metal-cutting circular saws, as noted below, standard circular saws can accept metal-cutting blades as long as the saw’s rpm matches the blade, which is usually near 3,000 rpm. For higher-rpm corded circular saws, finding a suitable blade could be difficult because the metal-cutting saws run at about 3,200 rpm while some of the circular saws run at 5,000 rpm or higher. Using a lower-rpm blade in a higher-rpm saw reduces blade life and increases injury risk.
Milwaukee Tools’ cordless 6320-21 18-volt 61/2-inch Metal Cutting Circular Saw ($300-$420), powered by a 2.4 amp-hour NiCad battery, cuts smaller diameter conduit and other metal shapes. Featuring 21/8-inch depth of cut and 3,200 rpm, the tool has an electric brake for quick blade stops, a spindle lock and onboard hex wrench for easy blade change. A clear-guard window and a blade on the left side offer unobstructed line of sight for right-handers. The tool, which has a cushioned-grip D-handle, comes with battery, universal one-hour charger and contractor bag.
Pipe cutters have long been popular options for conduit cutting. They are commonly used in conjunction with burr-removing reamers and conduit-threading equipment. They are most often used with portable power drives where the conduit is secured by the drive jaws while cutting, reaming and threading.
Featuring a drop-forged steel body and a chrome-plated shaft, Ensley Tool Division of Rothenberger USA Heavy Duty 4-inch Pipe Cutter 70060 sports hardened alloy steel cutter wheels that ensure burr-free cuts. Wide rollers help accurately guide the blade as it cuts around the pipe. The tool can be used with the company’s tri-stand chain vise for supporting pipe during cutting and threading. The cutter is also handy to use with portable power-threading equipment mounted on a tripod because, once the pipe is in the power drive, an electrician can cut, ream and thread the pipe from one working position.
Working with PVC conduit requires different tools than those used for metal. Gardner Bender PVC Conduit Cutter GPC 125A ($51.54) cuts flexible, watertight flexible and Schedule 40 PVC conduit 1/2-inch to 1 1/4-inch. A specially designed auto-blade return allows the blade to be exposed only during cutting, with a safety release button available to manually disengage the blade should a problem occur. A comfort squeeze handle with high leverage ratcheting action lessens fatigue during difficult jobs.
Carlon CC120B KWICKCUT Cutter, for cutting 1/2- to 1-inch Schedule 40 and Schedule 80 Rigid nonmetallic conduit, Liquidtight Flexible Nonmetallic conduit, and nonmetallic corrugated telecommunications raceway, is 8 inches long. The small-size conduit cutter, which is nonmetallic except for the blade, works like a pair of scissors and requires little force. The straight blade closes on a curved, nonmetallic edge.
Wire cutters for larger gauge wires can be powered by muscle, hydraulics or battery. Manual cutters may be suitable for applications with a limited amount of cutting. A ratchet mechanism or long handles for greater leverage can ease required effort. Hydraulic- or battery-powered cutters allow an operator to cut wire with less physical fatigue and less chance of repetitive-motion injury than manual cutters.
Many cutters have replaceable blades, and maintenance is vital for clean wire cuts. “Dull blades can cause the cut wire to flare, making insertion into the connector more difficult,” points out Carl Taylor, manager, Research and Development, ILSCO.
The 16-inch ILSCO CTR 750 manual wire cutter ($312), for cutting copper or aluminum cable up to 750 MCM, has a ratchet mechanism enabling users to cut conductors with minimal effort and an open/close lever to control the cutting blade direction. The replaceable cutting blades are made of precision ground steel alloy for long life. The tool’s length allows use in cramped areas.
Featuring a patented eccentric transmission that yields heavy-duty hand cutting, Weidmuller KT45 ($220) Ratcheting type cutter can slice through 750 MCM copper and aluminum cleanly, using relatively short 6-inch handles. The hardened-steel cutting blade has hips and valleys in its surface that facilitate slicing through, rather than pinching, cable, and has large, molded handles for increased ergonomics. The cutting blade can be released in any position within the cut or can be locked into position for transport.
For one-handed cutting of copper up to 400 MCM, and aluminum and communication and telephone cables up to 600 MCM, Klein ToolsLarge, finger-formed handles feature limit guards, for safety, and plastic covering for a nonslip grip. The lightweight, 10 1/4-inch tool reaches into tight work areas and can be locked into closed position for pouch toting. Ratcheting Cable Cutter 63060 ($185.28) features ratchet action that holds cable tight and allows rapid, straight cuts with mini mum effort. The tool has a hold-open spring to speed cutting and a quick-release lever that opens the blade at any time during the task.
Thomas & Betts hand-operated Hydraulic Cutting Tool TBM40HC, for cutting copper, aluminum and telecommunications cables up to 3.35 inches, has heat-treated, high-strength steel blades and features double-speed action: a fast-advancing speed for rapid approach of the blades to the cable, and a slower, more powerful cutting speed. The head opens easily to allow cutting of existing cable runs and rotates 180 degrees for optimal positioning. The unit features an automatic safety valve to bypass oil when reaching maximum pressure. A pressure release device can also be activated during operation.
FCI Burndy’s 12V-DC BCC1000 Battery Cable Cutter cuts 1,000 kcmil soft-drawn copper and 2-inch O.D. aluminum cable in limited spaces. The 6-pound tool has a forward-reverse-neutral switch that allows users to make partial cuts, back off cables or make adjustments during cutting. A wrist loop provides added security for overhead cuts.
With its variety of head components, Greenlee ECCX Gator Pro (SRP $2,245 plus blades) is a versatile, portable battery-powered hydraulic multipurpose tool for cutting and crimping wire and driving knockout punches. On one full charge, electricians can achieve 75 cuts on 500 MCM, using aluminum and copper blades that slot into the quick-release, flip-open head. The blade automatically retracts when the cutting cycle is complete. The tool, which comes with 2 Ni-MH batteries and a 120-, 220-, or 12-volt charger, features a 360-degree rotating head and an ergonomic angled handle. EC
The FELDMANS write for various magazines and Web sites. They can be reached at firstname.lastname@example.org or 914.238.6272.