Published In May 2000
Conduit benders go hand in hand with conduit - you can't bend the latter without the mechanical advantage and shape of the former. Good benders minimize time and effort and maximize the accuracy and precision of the result. Conduit benders fall into four general categories: hand benders, mechanical benders, electrical benders, and hydraulic benders. The kind you need on site depends upon the size and type of conduit to be modified. High-quality conduit benders boost productivity and efficiency, increasing the number of bends per hour without breakage of the bender, kinking of the conduit, or exhaustion of the electrician. All benders work toward the same goal: bending conduit into a curve of one particular degree or another to accommodate installation needs. Whether you need to bend conduit into a right angle with a tight or wider sweep or into a 30-degree offset or to another degree, it pays to have a tool that is durable and easy to use. On any project, delays resulting from bender breakdown can be very costly. Hand benders Hand benders, typically for one-half-inch through 1 1/4-inch conduit, are manufactured in either iron or aluminum. Because the weak points are, often, the hook and the handle socket, look for a unit where those points are reinforced or made of heavier-gauge material. Time-saving features worth shopping for include permanent markings on the bender that are useful as reference points for quick, accurate measurement of angles. Most manufacturers have at least some information cast into the long pipe handle. Consider the breadth and depth of instruction imprinted when buying for electricians for whom the bending is not already second nature. For example, imprinted deduct information would tell electricians where to start bending for a 90-degree stub. Most companies include a full complement of markings on each bender to aid in measuring angles when bending on the floor and as reference points for conduit placement during inverted bending. Some benders include a built-in spirit level for bending on the floor or side markings for bending while the tool is an inverted position. Alternately, if you buy a model that is configured so that when the handle is straight up you have effectively bent the conduit 30 degrees (the second most common bend to create), you won't have to worry about the accuracy of the bend angle. Other possible features include an arrow or star to indicate the starting point for back-to-back bending; offset multipliers, which provide information to create offsets of desired lengths; a flared handle, which is useful for adjusting half-inch stub-ups in concrete slabs; and a ribbed foot, which aids in applying maximum leverage. Many manufacturers, including Greenlee Textron, Gardner Bender, and Rothenberger USA, make malleable iron or aluminum hand benders. The aluminum benders are lighter. Mechanical benders A mechanical ratchet bender is used on one-half to 2-inch conduit, benefiting the electrician with the mechanical advantage the long handle provides. Since costs and types vary, it is important to select the correct model that is designed for a particular range of applications [e.g., for bending rigid conduit (heavy wall) only, for bending EMT (thin wall conduit) only, or for bending both along with IMC (intermediate conduit) on a universal bender]. If you need to bend a variety of conduit types on a random basis, you may want to get a universal-combination mechanical ratchet bender that will bend all three types of conduit. You would then use different shoes and follow bars for each type of conduit. In evaluating units, compare the specifications on the strength and structure thicknesses of various frames. Also consider construction of the ratchet mechanism. How durable is the mechanism likely to be? If your bending requirements are apt to vary, look for a unit that does a broad range of sizes, such as from one-half- to 2-inch EMT and one-half to one-and-one-half-inch rigid. While this type of bender would not be as productive, bend for bend, as an electric bender if you are bending this range only occasionally, you could do so without investment in the greater cost of an electric bender. Greenlee Textron's 1800 series of mechanical benders features several models including dedicated and combination units. The units include ratchet mechanisms for easy bending, along with the capability of bypassing the ratchet for fast, direct bending on smaller sizes, and bending degree indicators and charts to aid in accurate bending. All shoe and bending accessories can be mounted to the frame unit and secured with a locked chain. Gardner Bender's Sidewinder series of mechanical benders includes eight models for various types and sizes of conduit. A zero- to 90-degree bend indicator, built into the frame, shows bend angle during bending. A double-dog ratchet prevents shoe spring-back during bends and allows fast release after bending. The removable bender frame can be bolted to a workbench or truck bed for flexibility. Rothenberger USA's Combo Mechanical Bender requires only two shoes to make bends on one-half to one-and-one-quarter-inch EMT, rigid/IMC, schedule 40 steel pipe, and aluminum conduit. The bender, which sports a ratchet drive with positive release for larger-diameter pipe, has a spring-loaded brake system that applies pressure to the bending shoe, preventing shifts during loading and unloading procedures. The Lidseen "Chicago Bender" Model 5500 can handle one-half- to one-and-one-half-inch EMT, and one half- to one-and-a-half-inch rigid and IMC conduit without having to change shoes, because the shoes sizes are all built in. Bends with larger-than-standard radius are made using the groove for the next-larger size, giving a trifle more flattening at the bend which, notes the manufacturer, is not usually visible and is well within code requirements. Electric benders Electricians who bend one-half- to 2-inch conduit frequently will survive the workday in a lot better shape if they use electric benders. While some electric benders are dedicated to either EMT or rigid conduit (the latter of which may offer separate attachments for bending EMT or IMC, as well), top-of-the-line benders are, typically, combination units that bend EMT, IMC, and rigid without changing any shoes. However, if you are looking for portability, it is easier to relocate a lighter-weight bender that comes with separate attachments than a heavier combination unit. An electric bender, which makes the bend in one operation, typically has a large scale marked in degrees and a pointer on the shoe. On many models, the user bends the conduit until the pointer indicates the desired angle and then a bit beyond (according to chart specification), to compensate for spring-back. Some electric benders, however, offer digital read out, which allows automatic compensation of spring-back. Greenlee Textron 855 Electric Conduit Bender for EMT, IMC, rigid, and rigid aluminum, features a split-roller system, so you don't have to change rollers when going from EMT to rigid. The unit, which can bend in vertical or tabletop positions, sports a digital read out and programmable bend angles, which facilitates accurate repeat bends. An optional interactive control calculates complete layout measurements for various types of bends. The unit also has the capability for field adjustment of the squeeze, accommodating conduit variations, points out the manufacturer, so you don't get wrinkles on the inside of the bend. Rothenberger USA model E-688 High-Speed Bender, for bending one-half- to 2-inch rigid, IMC, EMT, and 40-mil PVC-coated conduit, operates horizontally or vertically and bends 2-inch conduit to 90 degrees in 16 seconds. The unit features a double-relay solid-state controller. An adjustable limit switch allows for consistent, identical repetitive bends. The model also includes a remote pendant control for forward and reverse operations, a built-in protractor that indicates degrees of bend desired, and a built-in bending chart providing information required for bending offsets or 90-degree stubs. Gardner Bender Cyclone B2000 bender bends one-half- to 2-inch steel (schedule 40 max) and aluminum rigid IMC and EMT conduit all on one shoe, as well as one-half- to 1 1/4-inch PVC-coated conduit on the EMT shoe in the next larger groove. The unit, with a 12V remote control, operates in two working positions: horizontal, for table-top bending; and vertically, for accurate offsets. For automatic bending, the operator sets the indicator on a rotary dial to the type of conduit and degree of angle, facilitating easy repetitive bending in 12 to 16 seconds. Hydraulic benders Hydraulic benders, for bending 2 1/2-half- to 5-inch conduit and driven by electric power pumps, are available either as dedicated units or as combination models that bend three types of conduit. The combination hydraulic benders, which can handle up to four-inch conduit (the maximum sizes of EMT and IMC conduit), are the most popular. With some models, users can make a full 90-degree bend in one shot or can use segment bending to make a larger sweep. Because the outside diameters of EMT, IMC, and rigid conduit in these larger size ranges all have very similar outside dimensions, conveniently, there is no need to change shoes when using combination hydraulic benders. Optional bending tables, often sold with hydraulic benders, offer a comfortable working height in relation to the bender, which would otherwise be on the floor. They also help keep all critical parts aligned properly for consistent bends. Greenlee Textron and Gardner Bender offer wide ranges of hydraulic benders and accessories. Companies mentioned in this article include: Gardner Bender, www.gardnerbender.com, 414-352-4160 Greenlee Textron, www.greenlee.textron.com, 800-435-0786 Lidseen Benders, 800-742-3538 Rothenberger USA, www.rothenberger-usa.com, 800-545-7698 William and Patti Feldman are writers, editors, and authors who provide Web content and write for magazines, trade associations, building product manufacturers, and other companies on a broad range of topics. They can be reached at firstname.lastname@example.org or (914) 238-6272.