# What are the actual degrees required to achieve a perfect 30, 45 and 90 degress bends



## robbiie (Oct 7, 2018)

This is a question I have for using a hydraulic bender.

As we all know, hydraulic benders become less accurate over time. Fortunately, i have a digital level that can give me actual degree readings regardless. What i am asking is, does anybody have a chart or something similar that lists the actual bend in degrees you need to achieve a 30, 45 or 90 degree bend on a hydraulic bender?

ie, to get a perfect 90 degree bend on 2" emt. You must actually bend the EMT at 93 degree to compensate for kickback. (93 i made up but you understand what i am implying)

if possible, it would be great to have the numbers to overbend for 2" emt and above and in those degrees.

Thank you in advance.


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## HackWork (Oct 2, 2009)

No one can tell you because it depends on the bender. Not only the model, but the age (as you mentioned).

You can figure it out in the first couple bends.


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## robbiie (Oct 7, 2018)

dang.
Thanks for the response.


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## 360max (Jun 10, 2011)

I agree with Hack, each bender has its own deductions to make accurate bends. Sometimes there is no difference between the same brand of benders, sometimes there is a slight difference.


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## robbiie (Oct 7, 2018)

but regardless of the bender, all 4", 3", 2.5" etc EMT would spring back the same amount correct? but i guess it depends on the manufacturer of the EMT also...


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## HackWork (Oct 2, 2009)

robbiie said:


> but regardless of the bender, all 4", 3", 2.5" etc EMT would spring back the same amount correct? but i guess it depends on the manufacturer of the EMT also...


No. I have had to use different amounts on different benders. Like I said, it is very easy to see what you need to use in the first couple of bends.


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## TGGT (Oct 28, 2012)

Digital level is exactly how you figure this out.

When it comes to big rigid, taking a little out isn't always practical.

+2.5* is my go-to, usually pretty close. Otherise, for a 90, go to 91*, release the pressure on the bender very slightly, enough that you can see it spring back, but not enough for the pipe to slip in the shoe. Zero out on the long end and then check the stub. Bend again going a degree or 2 more and repeat until you got your "perfect" 90. Make note of the reading on the level and the mark on the bender. After 2 or 3 of these you should be able to bend in 1 shot, especially if making many identical bends.

Less than a +/- .5* I can live with on exposed runs in high traffic areas.

If the conduit thickness changes (emt/imc/rigid) or the size pipe changes, or the bending shoe/brand changes it will all change the spring back degrees.

Sent from my SM-G930T using Tapatalk


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## Bird dog (Oct 27, 2015)

OP please fill out your profile as this site is for electrical pros only. Otherwise, please post on...
https://www.diychatroom.com/


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## cabletie (Feb 12, 2011)

I'm not sure if the numbers are about the same, but the Evans bender says 5% for 45, 10% for 30 and 20% for 15 degrees. On their bender it's worth doing the extra math. It comes out dead on. It sucks having to take it out, only to find out your offset is an Inch shy. I don't know how those numbers would relate to degrees, because on their bender you multiply the height of the offset by the percentage. You could try 45 times .10 and get 4.5. So bend it to 49 to 50 degrees and see what happens? There is more spring back on smaller degrees. 

Otherwise, for larger conduit, I do it as described by everyone above. 

2" EMT with a hydraulic bender must mean the Greenlee flip top bender? Probably the biggest time waster of all benders. Without a doubt I would go manufactured bends before wasting time like that. 

http://evansbenders.com/index.php/page_id/5/osCsid/11d215b3cfc39a67dc71863e58de846e


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## TGGT (Oct 28, 2012)

cabletie said:


> I'm not sure if the numbers are about the same, but the Evans bender says 5% for 45, 10% for 30 and 20% for 15 degrees. On their bender it's worth doing the extra math. It comes out dead on. It sucks having to take it out, only to find out your offset is an Inch shy. I don't know how those numbers would relate to degrees, because on their bender you multiply the height of the offset by the percentage. You could try 45 times .10 and get 4.5. So bend it to 49 to 50 degrees and see what happens? There is more spring back on smaller degrees.
> 
> Otherwise, for larger conduit, I do it as described by everyone above.
> 
> ...


I've never seen one of those offset machines before, that's cool it does both bends at the same time, no releasing, flipping and sliding and worrying about dogs.

Sent from my SM-G930T using Tapatalk


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## eddy current (Feb 28, 2009)

Bird dog said:


> OP please fill out your profile as this site is for electrical pros only. Otherwise, please post on...
> https://www.diychatroom.com/


I agree he should fill out his profile, but I don’t think there are too many diy’ers out there with hydraulic benders


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## Bird dog (Oct 27, 2015)

eddy current said:


> I agree he should fill out his profile, but I don’t think there are too many diy’ers out there with hydraulic benders


True :smile:


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## cabletie (Feb 12, 2011)

My employer has two of them. When there on a job they get used a lot. I don't know if they know they make a double 3/4" shoe for it. I'll have to tell him on the next job where there's a lot of 3/4 to bend. As it is, it's great for repeatable bends. 

Guys usually hang their cardboard notes on it. So if you typically have to do like a 2-1/2" offset to come down off a bar joist into a box with 10 degree bend, your numbers are there. 

I have a spreadsheet I made that I hang on the bender. So most of the time I don't have to do any math. It's set up for kicks too. Just read the measurement and mark from back of 90 to back of traveling shoe. The hard part, if you don't have a protractor, is making sure your finished at the right angle. 

I bought level vials and rare earth magnets a year ago. I was going to make my own wood wedges with the level vials in them for the common degrees. Make a separate one for each common degree. Leave them stuck to the bender or make them small enough I could even keep one in my pouch. 

They have the shotgun shoe for the electric bender too. That thing is expensive in the catalogue, but they use the hell out of it, so I'm sure it's paid for itself.


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## bostonPedro (Nov 14, 2017)

There is no chart or formula. 
Green digital triple nickels have a chart on the bender but they are off by a degree or 2. Currently have one onsite that I use.

I also am using a Southwire bender and adding 6 degrees seems to be the magical number on that bender for offsets......right now but 4 months ago it was different. For 90's this machine is 98 degrees with 2 jogs but it used to be lower. 


Its funny because we were discussing in work last week how we wished companies would calibrate the benders for spring back


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## macmikeman (Jan 23, 2007)

All I know is I take my 555 to 93 for 2" rigid and it gets a perfect 90. It will bend 20 other pipe combinations/sizes , but that is the one I hit most- 2" rigid so that one I noted onto the bender....


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## bill39 (Sep 4, 2009)

robbiie said:


> but regardless of the bender, all 4", 3", 2.5" etc EMT would spring back the same amount correct? but i guess it depends on the manufacturer of the EMT also...


I believe the differences in springback are mainly due to the hardness of the pipe. Try using the "Amount of Travel" method of bending to compensate for springback.


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## Southeast Power (Jan 18, 2009)

We bought a new degree sticker for a 555 we have.
I spent an hour with an apprentice bending some 3/4" rigid.
We put all of the marks above the sticker and moved the zero degree to where it would make 90 degrees at the 90 degree Mark.
It worked perfectly.
Until we bent some 2" rigid.
New marks were made on my new sticker. :sad:


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