Electrical conduit protects wires running through walls or outside from the elements and provides extra protection for surrounding structures from the wires. Installing wire requires knowing how to bend electrical conduit. To do the job well, you’ll need extensive practice to learn and master various bends. Reviewing the basics periodically, regardless of your level of mastery of conduit bending, ensures you do the process safely and accurately every time.
Table of Contents
Tools You Need for Conduit Bending
You will need several essential tools before starting the bending process. These include the following:
Tape Measure, Level and Framing Square
To ensure accurate cuts and level conduit, you need a tape measure, a quality level and a framing square. Check that your tape measure is sturdy enough to stand out without support for at least 10 feet, especially if you need to work in the air with a conduit.
The level you choose should have strong magnets to hold it against the conduit, even when placing the tubing overhead. Additionally, 30-degree angles marked on the level and easy-to-read markings are other beneficial features for levels used for conduit bending work.
A framing square will assist in checking the angle of the conduit after bending. Like the tape measure, this square should be sturdy and easy to use.
Conduit benders typically come in steel or aluminum options. Steel conduit benders generally cost less but weigh more. If possible, avoid using a steel bender for doing long projects because the weight will cause fatigue sooner with use. Whichever material you use, verify that the bender will accommodate the conduit size.
In addition to the tool’s material, look for a degree scale and multiplier values on the bender. Having these values on the bender reduces the need to refer to a separate conduit bending chart for shrinkage calculations.
Other markings on the bender to look for include:
- An arrow: An arrow lines up the marks for the outer and offset parts of a saddle bend.
- A star point: A star point shows the back side of a 90-degree angle in back-to-back bends.
- A rim notch: A rim notch indicates the center point of a three-point saddle bend.
Lastly, choose a bender with a handle or prepare to create your own from a pipe cut to fit.
Pencil or Marker
You’ll need a pencil or permanent marker to mark measurements for where to cut the conduit to avoid measuring and cutting mistakes. Use a pencil if marking exposed conduit. Tubes that show will typically have a coating of paint to camouflage them, but a permanent marker on the conduit can bleed through the paint.
Conduit Bending Chart
A conduit bending chart gives the amount of take up in length for various diameters of conduit bent to different angles. One of these charts should be part of your conduit bending materials to avoid fit errors. It also helps with providing the values needed for making calculations for creating saddle bends and offset bends.
Electric metallic tubing (EMT) made from aluminum or stainless steel is one of the many types of conduits you may use. This form often has applications for interior residential or light commercial structures. Know the diameter of the EMT you work with because the conduit bender must match the size of the EMT.
Pipe Cutter or Hacksaw and Slip-Joint Pliers
The cutting tool used for the conduit could be a pipe cutter or hacksaw. Both easily cut through metals used for conduit construction. Include a pair of slip-joint pliers in your cutting tools kit to hold down the conduit and free one of your hands while cutting. You can also use the pliers to remove burrs from the outside of the EMT after cutting.
Screwdriver or Conduit Reamer
Removing burrs from inside the conduit after cutting is faster with a flathead screwdriver. A conduit reamer works better if you have one available.
Prepare for Your Electrical Conduit Bend
Before bending, you need to prepare the conduit for the process. Measuring, marking, cutting and cleaning the conduit will make the final process of creating the necessary bends easier.
- Measure and calculate distance: Measure the total distance for the conduit. Use a conduit bending chart or the multiplier notations on the bender to determine the amount of take up. The value depends on the conduit’s width and the degree of the bend. For instance, the bender may indicate a 5-inch take up for a 90-degree bend. This means you need to add 5 inches to your total length for one 90-degree angle or 10 inches for two 90-degree angles over the length of the conduit.
- Measure and mark the conduit: Carefully measure the conduit with a tape measure and mark the length. Verify your distance by measuring the conduit again before cutting to avoid cutting the piece too short or too long.
- Cut the conduit: Hold one end of the conduit against a workbench with a pair of slip-joint pliers while cutting the other end with a hacksaw at the marked spot.
- Remove burrs: Clean out burrs from inside and outside the conduit at the cut site. Use pliers to clear off burrs from the outside and run a flathead screwdriver inside the conduit to clear out interior burrs.
How to Bend an Accurate Stub or Right Angle
An accurate stub, also known as a stub up or a 90-degree bend, is the most basic type of bend. Beginners learn this kind first because it is simple and very commonly used. When making this type of bend, you’ll need to know the take up and the height stub up:
- Take up: This is the amount of conduit you need for the bend.
- Height stub up: This is the distance from the bottom of the 90-degree bend to the end of the conduit.
For example, if you need a 15-inch right angle bend and the bender has a 5-inch take up, you will have a height stub up of 10 inches from the bottom of the bend to the end of the conduit. Mark this spot with a marker to indicate where to line the arrow on the bender.
Use the following steps to create your 90-degree bend:
- Set the bender on the ground with the handle pointing toward the ceiling, and slide the end of the conduit into the bender.
- Use the markings on the bender to find the start and end of the 90-degree bend. Depending on the bender brand, these markings may be letters or an arrow and star.
- Place the EMT into the bender to align the mark with the arrow.
- Press one foot firmly on the back side of the conduit that will remain on the floor. Put the other foot on the bender heel to slowly bend the conduit to a 90-degree angle. The back of the conduit should align with the star symbol on the bender.
How to Make Back-to-Back Bends
A back-to-back bend involves creating a bend from the back side of a stub. This bend makes a widened U-shape to move the conduit down a vertical surface and along the floor before moving up to another vertical surface.
- Measure the distance between the two parallel surfaces to find the distance between the stubs you will make for the back-to-back bends.
- Create the first accurate stub. Measure along the free end of the conduit to mark the location of the back of the second bend. Use the distance you measured in step one for this section.
- Place the marked part of the conduit into the bender at the star.
- Apply firm pressure on the conduit to hold it down while pushing your other foot on the bender heel until the conduit end reaches the arrow on the bender, indicating the creation of a second 90-degree angle and the completion of the back-to-back bends.
How to Make an Offset Bend
Offset bends adjust the conduit course to move around an obstruction. To create this bend, make two bends in opposite directions. Most benders will have the degrees to use for offset bends marked on them, including 22.5 degrees, 30 degrees, 45 degrees and 60 degrees. Follow these steps to create an offset bend:
- Measure the distance to the object. Find the offset distance by measuring how far the conduit needs to change its direction to clear the obstacle.
- Use a conduit bending chart that includes offset formula values to find the shrinkage per inch of offset based on the two offset angles you want to make. The location will determine the type of degree measures to use for the offsets.
- Multiply the shrinkage per inch by the offset distance to find the total length of conduit you need.
- Add the total shrinkage to the distance to the object. Measure and mark this distance from the end of the conduit.
- Multiply the offset distance by the constant multiplier from the offset chart to find the distance for the second mark from the first. This mark indicates where to make the first bend.
- Measure the offset distance from the second mark and mark where to make the second bend, which will go in the opposite direction.
- Bend the end of the conduit as you would for a stub until you reach the needed angle for the first offset. For instance, if making a pair of 45-degree angles, make the first bend to the 45-degree mark on the bender.
- Turn the conduit upside down to create the second bend in the air to the same degree as the first bend.
How to Make a Saddle Bend
Saddle bends are similar to offset bends but return the end of the conduit to the same plane after passing around the obstacle. These types of bends have three points to them. Use the following to create this type of bend:
- Measure the distance to the middle of the object and the height of the offset.
- Choose either a 45-degree or 60-degree center angle for the saddle bend. The other two bends will each measure half of this center angle. So, a 45-degree angle will require two 22.5-degree angles, and a 60-degree center has a pair of 30-degree angles.
- Use a saddle bend chart to find the distance to the first side bend. Use the obstacle’s height and the shrinkage listed on the table based on the central angle to determine where to make the first mark. Add this shrinkage to the distance to the object’s center to calculate the distance to the center mark. Measure and mark this distance.
- Use the saddle bend chart to find the distance off the center mark based on the obstacle height and center angle. Subtract this value from the center mark for the first bend location. Add this value to the center mark for the second bend location. Measure and mark both bend locations on the conduit.
- Make the center bend to 45 or 60 degrees.
- Make the first side bend on the floor to the 22.5- or 30-degree mark, depending on the center angle.
- Turn the conduit upside down to create the second bend in the air. Unlike a second offset bend, rotate the bender 180 degrees so the second bend returns the conduit to the same plane to complete the saddle bend.
How to Bend With a Hickey
A hickey is another tool for bending conduit. However, this hand bender requires extra work because it can only create very small angle bends. For instance, instead of simply bending conduit to 90 degrees as you could with a bender, you would need to complete nine 10-degree bends with a hickey. You create the first 10-degree bend, move the hickey down the conduit and bend the tool to make the second bend. Continue until you’ve completed making the total bend.
When bending EMT, do not use a hickey because it can crimp the conduit. Only use this method for bending rigid conduit.
Bending in Air vs. on the Floor
In most cases, bend conduit on a sturdy floor. Avoid using carpeted floors, and only bend in the air when the project requires it. Carpeting can lead to conduit crushing, and air bending may not be as easy to do for beginners as using the floor.
Mistakes to Avoid When Bending Electrical Conduits
When bending electrical conduits, avoid the following common mistakes:
- Misplaced pressure: Don’t put too much pressure too far from the bender or at the bent part of the conduit. Excessive pressure or pressure in the wrong spot can create a flattened or buckled conduit.
- Incorrect tools: Using the incorrect tools will make bending conduit correctly difficult. For instance, using a hickey with EMT can cause it to flatten because this type of bender is only for rigid conduits.
- Extensive flattening: Extensive flattening can happen from improper pressure or using the wrong tools. Trying to bend conduit on a carpeted floor could also cause flattening problems.
- Lack of pressure support: Air bending often causes a lack of pressure support for the conduit because you have to hold up the conduit while working with it. Lack of pressure support may cause the conduit to slip inside the bender and fail to bend correctly.
- Incorrect lines on benders or sighting lines wrong: Not using the sighting lines on the bender or improperly marking your conduit can also cause problems when bending the conduit. Measure each mark twice before bending.
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