Dan has been a licensed journey-level electrician for some 17 years. He has extensive experience in most areas of the electrical trade.
EMT Pipe Bending
Bending EMT is one of the more common tasks for both commercial and industrial electricians, and it is not difficult to learn. This article is designed for the beginning electrician, that they may pick up some pointers in using a hand bender to make a 90-degree bend in electrical conduit. More experienced electricians may be interested in another article on how to make a concentric bend.
There are three basic 90-degree bends: the plain 90, a kick 90 and a double 45 90. Each has its uses and should be learned by the electrician; each will be treated separately in this article. Read and understand the conduit bending instructions here and try to get some "bones" (scrap conduit) from a job site to practice on. A little practice and you will quickly become proficient at bending a 90.
How to Make a 90-Degree Bend
A simple 90 degree bend in electrical conduit; it sounds easy, and it is, but there are a few considerations to make. First on the list is to understand the term deduct; this is a measure of the amount the conduit will "shrink" in length when a hand bender is used properly. It is different for each size of bender (½", ¾" and 1" benders) and some brands of benders are different as well. The most common deducts are 5" for ½" conduit, 6" for ¾" conduit and 8" for a 1" bender. It is a function of the curvature radius of the bender and cannot be changed. The deduct for your bender should be stamped on the bender.
To use the deduct figure, measure the distance to the far edge of the 90 and subtract the deduct figure. If ½" pipe is being bent and the distance is 56" place a mark on the conduit at 51"; this is where the bender will be placed.
Work the bender onto the conduit with the conduit mark at the arrow of the bender. There are some slight variations in the location of the arrow on different brands, but it is basically at the beginning of the curve of the bender. The bender must be oriented with the toe of the bender pointed toward the end of the conduit measured from. To phrase it differently, point the toe of the bender toward the end of the conduit where the tape measure was hooked to measure from.
With the conduit on the floor apply firm foot pressure to the foot pedal of the bender and slowly move the handle of the bender toward the floor. Much of the bending pressure will come from the foot pedal - if there is not enough pressure on the pedal the conduit will kink instead of making a smooth bend. As the conduit rises into the air, grasp it with your free hand and apply a small amount of pressure there to steady it. It is good practice to stop bending just before it appears to be a true 90-degree bend and check it with a level. It is easy to add a few more degrees; not so easy to take some out. Be aware that the weight of the bender will cause a small amount of bend that will disappear when the bender is removed and the conduit springs back very slightly.
The above method works well for shorter lengths, but when a long measurement is needed it will not work. For instance, if the measurement is 110" in a 120" length of conduit the bender will have only 10" to work with and it is difficult to impossible to make such a bend, particularly in ¾ and 1" conduit. The answer is to turn the bender around and point the foot pedal toward the end measured from. Do not use the deduct! Mark the conduit at the full length desired and again work the bender onto the conduit. This time, line up the star on the side of the bender, about half the way around the bender, with the mark. Bend as before. This method of measurement and bender placement is commonly termed a "backbend"
Bending a 90
Bending a 90-Degree Bend
Bending a Kick 90
A kick 90 is, very simply, a 90 with an additional small bend in it, either raising or lowering the end of the 90. It might be used on a conduit going up inside a wall but that needs moved over and outside the wall when it continues, via the 90, on the ceiling. The same thing can be accomplished with a 90 and an offset, but this requires additional bending and makes wire harder to pull. Always limit the number of degrees of bend in a conduit run to the minimum possible.
First bend the 90 and choose a spot to add the small "kick" bend. The closer to the 90 it is the more degrees it will require, but at the same time if it is too far away from the 90 it will look decidedly odd. Mark the conduit and place the bender mark for a normal 90-degree bend at the mark. Make sure the 90 is turned the proper direction or the kick will be bent the wrong way. Visualize the resulting conduit before bending, perhaps while holding it in the proper orientation. Normally kicks are bent to a particular measurement in inches rather than degrees. With the bender in place on the conduit and on the floor ready to bend, apply pressure to the bender, but just enough to tighten up on the conduit so it doesn't slide or turn. Verify with a level that the 90 end is level, and measure from the floor to the top of the conduit 90. Measure how high the 90 is from the floor (see pictures).
Begin to bend, watching the tape measure carefully until the conduit is at the correct height. Be careful not to allow the bender to lean to one side; while this won't change a bend that is already started it will change the reading on the tape measure. The measurement to look for will be the desired kick amount plus the first measurement taken. For instance, if the first measurement is 1 ½" (a reasonable amount with the bender just tightened slightly) and the desired kick is 4" the final measurement to the top of the conduit should be 5½", Also be aware that the side of the 90 with the kick will shrink in length; the shrinkage is extremely variable so it is best to simply make the 90 too long if that is where the kick will be and cut to the right length.
A Kick 90
A Double 45-Degree 90
The final method of making a 90 is to make two 45 degrees instead. There will sometimes an obstruction in the corner of two walls or a wall and a ceiling where a typical 90 needs to pass. The answer here is to bend two 45 degree bends with a short section of straight conduit between them. The total bend is then 90 degrees, but the path the conduit follows misses the actual corner of the wall.
To make the bend, measure the distance to the corner (not the obstruction). Decide how far back to make the first bend so that the conduit will miss the obstruction if bent at 45 degrees. Just a little practice here and you will become quite proficient at making this call. Deduct that measurement from the one to the wall and then subtract 1 more inch. The extra inch is necessary as conduit is not a thin pencil line, but a thick 3-dimensional object making rounded bends instead of sharp corners.
Example: Distance to wall is 50", it has a 3" round pipe right in the corner and you feel that making a 45-degree bend 6" from the wall will clear the pipe. Mark the conduit at 43" (50" - 6" - 1"). Now multiply the 6" figure by 1.4 (6" X 1.4 = 8.4" or about 8 3/8") and make a second mark 8.4 inches past the first mark. Using the notch that indicates the center of a 45-degree bend to line up with the first mark, make a 45° bend; slide the conduit forward in the bender and, making sure the conduit hasn't turned in the bender, repeat the process. You now have a 90° bend that will miss the corner obstruction.
Many electricians prefer to make these smaller bends "in the air" as it is much easier to get the proper bend. If you are not sure about this, a good read might be EMT Electrical Conduit Pipe Bending Instructions, which includes a section on bending offsets in the air.
A final note: This article is but one of several written by an electrician, for electricians. A comprehensive guide to bending conduit has been written that gives a brief description of each page, along with a link to individual pages as well as a handful of other links to pages electricians might find useful. Feel free to check out this title page for anything else that looks interesting. If you don't find what you are looking for, leave a comment and it will be considered for future pages; the whole series is, and will continue to be, a work in progress.
Bending a Double 45
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: What is the maximum number of bends allowed in a conduit before you are required to install a junction box?
Answer: There is no limit on bends, but the limit on degrees of bend is 360 degrees. Four nineties, 36 ten degree bends, 8 45 degree bends; these are all at the limit.
© 2010 Dan Harmon
Dan Harmon (author) from Boise, Idaho on March 18, 2020:
As explained, this is a function of the bender, not an automatic figure good for everything. You will have to check your bender to find out. They vary.
John on March 18, 2020:
How much deductions for 2 in. and 4in.
Dan Harmon (author) from Boise, Idaho on June 21, 2019:
@Javier: You are allowed 360 degrees of bends before a J box is required. It might be in 4 bends or 10, but the total degrees of bend must not exceed 360.
mbrio on January 25, 2017:
Thanks man! I was trying to do a double 45 and couldn't get it to work. I knew I was doing something wrong but couldn't figure it out. Thanks again!
Dan Harmon (author) from Boise, Idaho on August 16, 2016:
You are limited by code to 360 degrees between junction boxes. Distance makes no difference, just that there be no more than 360 degrees before a second box is installed.
Mohsen on July 31, 2016:
Thank you for comprehensive descriptions
are there any limitation in number bending of 90 degree or 45 degree bending in EMT?
in other word how many bending of 90 , 45 is permited in 6 feet EMT?
Dan Harmon (author) from Boise, Idaho on April 01, 2016:
Yes, that works pretty well. It's only when you need to be with 1/8" or so that it begins to fail, and that's seldom necessary. Maybe with a big rack of pipe, but how often do we put a kick 90 into a rack? I've had to do that, but seldom.
Sparky2132 on April 01, 2016:
Whenever I'm kicking a 90 I use the same multiplier add I'd in doing an offset. Say I need a 7" kicked 90 i multiply by 2" (if I'm using a 30° bend) mark the pipe at 14 " from the back of the 90 then bend to 30° boom. It works with all degrees I tend to use 10° because it pushes the kick father from the 90 and keeps the degrees in the run down. Just don't forget of your visit had more than one 90 in it double check that it's plumb and level in all directions. Take the time, do it right, and make it look good. Remember bending conduit is an art form. There's no better feeling when your done with your runs and people are taking pictures and making phone calls about your work. The best description I've been given about my pipe work is, "it looks like water flowing!"
Dan Harmon (author) from Boise, Idaho on March 22, 2016:
Apologies. I will re-write that section. But briefly, with the 90 already bent, set the conduit bender in place and apply just enough pressure to tighten it on the pipe but not enough to bend the kick yet. Measure how high it is from the floor. Add the amount of kick and bend to that height.
How high the pipe is will vary with pipe diameter (if you measure to the top, and that's easier than trying to read the tape at the bottom of the conduit), how long the kick is (how far from the 90 the kick is) and with the brand of bender (mostly how thick the metal of the bender is).
Thanks, Carol, for the tip that it was unclear.
Carol on March 22, 2016:
In your description of kick 90, you say to add 1.5 inches to the "first measurement" but I find not description of measuring anywhere in the kick 90. I would love to understand how to measure and mark for this.
O from New York on October 24, 2015:
Very cool hub and helpful! I am now following you.
juliajohn24 on May 01, 2014:
You guys present there are performing an excellent job.
Dan Harmon (author) from Boise, Idaho on July 11, 2012:
No. A short radius, now illegal, but never a long radius.
Mark Ericksen on July 11, 2012:
Did you ever use the ericksen long radius bender?