From measuring to marking to cutting, conduit bending is truly one of the fundamental tasks for an electrician.
Conduit bending is truly one of the fundamental tasks of the electrical construction industry. Whether EMT, galvanized rigid steel conduit, or intermediate conduit, you will need to bend it. Bends will be required as part of your installation. Of course, factory-made elbows are available for feeder sizes (11/4-in. and higher). However, for branch circuit sizes, the trusty hickey is the tool of the day. Let's look at the following step-by-step approach.
Step 1: Remove cutting burrs from the cut conduit end. Before you begin your bend, use a conduit reamer to remove any cutting burrs left after you've made your cut. Some electricians use a knife to swipe the edge of the cut. Don't use a screwdriver; it's not meant for this task and really doesn't work as well.
Step 2: Mark the distance at which the conduit must change direction. Determine where you want the conduit to start. This is usually where the conduit secures inside a fitting. Then, determine where you need the conduit to change directions. For example, if you need a horizontal conduit to run vertically 5 ft from its starting point, then you need the conduit to change directions at 5 ft. Thus, make a mark on the conduit 5 ft from its start point.
Step 3: Mark the middle of the bend. If you need a 90 degree bend 5 ft from the conduit's starting point, then the middle of your bend is going to be somewhat less than the 5-ft distance. Many hand benders have the difference number you need noted right on them. If there is no number, remember this difference equals the radius of your bender. Most benders will have a mark that says "90." Simply measure from that mark to the mark "0." Then subtract that distance from the "change of direction" distance. This is the middle of your bend. Write this number, calling it "bend." Make the measurement near the bottom of the bending shoe, as close to the centerline of the conduit as possible. Mark the conduit to show the middle of the bend.
Step 4. Verify marks will make correct bend. Hold the conduit up to where you intend to install it. Do the "change of direction" and "middle of the bend" marks line up with the result you want? If not, measure again. Remember the motto: "Measure twice, bend once."
Step 5. Make a second verification. Lay the conduit on the floor with the "start" end against the wall. Measure from that end of the conduit until you reach a distance equal to the "bend" number you calculated earlier. Does this line up with the earlier mark you made? If so, continue with the next step.
Step 6: At the middle of the bend, mark a line on the floor. Place the "start" end of the conduit against a wall. Slip the hickey over the other end and line it up with the "bend" mark. If the hickey has a mark that reads "0," line up that mark with the "bend" mark. Pull up on your bender handle until the conduit is vertical. If your bend isn't perfect, you can adjust it by moving the hickey a little to one side of the bend and pulling slightly.
In Part Two, we'll look at how to make an end bend and an offset.