# Conduit Review Questions



## Derek.bick (Sep 21, 2013)

Hey I'm new to the site, Have a few questions for my class on conduit, can anyone help me out?

1) A 1/2 " Conduit must cross another conduit that is 16" away from a junction box.

Assuming a 60 degree center bend with an offset of 4", answer

A)What is the distance from the box to the first bend?
B) Which bender mark do you use for your first bend?
C If you use 60 degree for the first bend what do you use for the others?
D) What is the distance between the bend?
E) If the total length of conduit before bending was 10' what is the length after the bend is finished?

2)If a 10 inch 90 degree bend is put on a 60" piece of 1/2 " conduit, what will be the length of the pipe from the back of the 90 degree bend to the end of the pipe?

3) a 1/2 " conduit needs an offset to rise above an obstacle that is 40 inches away from the box, the obstacle is 7 inches high.

A) From the end of the conduit, at what distance do we make our first (farthest) mark?

B) What is the distance between bends?

These questions are the only ones i didn't know how to do, thanks for any help in advance.


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## freeagnt54 (Aug 6, 2008)

Derek.bick said:


> Hey I'm new to the site, Have a few questions for my class on conduit, can anyone help me out?
> 
> 1) A 1/2 " Conduit must cross another conduit that is 16" away from a junction box.
> 
> ...




http://www.idealindustries.com/media/pdfs/products/guides/conduit_bender_guide.pdf

All that info can be figured out from this guide. If you have a more specific question i'll be glad to help.

Or you can bribe me with a new wera screw driver on Amazon and ill give you the answers.:whistling2:

Edit:

Table 3-2. Bender gain table
Size of Conduit	90° Gain

1/2-inch EMT---------2 5/8 inches
3/4-inch EMT---------3 1/4 inches
1-inch EMT----------------4 inches
1 1/4-inch EMT-------5 5/8 inches


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## Derek.bick (Sep 21, 2013)

Thanks for the help but I'm still not really getting it, I would pay you if I could afford to but I am a student.


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## Big John (May 23, 2010)

Derek.bick said:


> 1) A 1/2 " Conduit must cross another conduit that is 16" away from a junction box.
> 
> Assuming a 60 degree center bend with an offset of 4", answer
> 
> A)What is the distance from the box to the first bend?


 A) Figure out your shrink and you can figure this out.


> B) Which bender mark do you use for your first bend?


 B) What's the order for bending a saddle?


> C) If you use 60 degree for the first bend what do you use for the others?


 C) Hint: All the bends in a saddle have to add up to zero.


> D) What is the distance between the bend?


D) Use your multiplier times the offset height.


> E) If the total length of conduit before bending was 10' what is the length after the bend is finished?


 E) Subtract you the shrink from both offsets.


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## 360max (Jun 10, 2011)

http://www.porcupinepress.com/_bending/saddles.htm

best bending site on the web IMO, has every bend except the compound 90


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## Derek.bick (Sep 21, 2013)

So this is what I got, tell me if i went wrong

A) 16" + 2"(60 degree angles shrinkage per inch of rise = 1/2", so 1/2 x 4 =2)
=18"

B) Middle Angle (60 degree)

C)30 Degrees

D)8 " (Multiplier of 30 degree is 2, 2 x4 = 8)

E) 8" (1/4=shrinkage per inch for 30 degree, 1/4 x 4 =1", so you would subtract 1" + 1" from 10" to give you 8").

Can someone correct that?


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## Big John (May 23, 2010)

You've got most of it.


Derek.bick said:


> ...A) 16" + 2"(60 degree angles shrinkage per inch of rise = 1/2", so 1/2 x 4 =2)
> =18"


 Double check that. Think of it like an offset bend.


> E) 8" (1/4=shrinkage per inch for 30 degree, 1/4 x 4 =1", so you would subtract 1" + 1" from 10" to give you 8").


 You're mixing feet and inches, but on the right track.


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## freeagnt54 (Aug 6, 2008)

Derek.bick said:


> So this is what I got, tell me if i went wrong
> 
> A) 16" + 2"(60 degree angles shrinkage per inch of rise = 1/2", so 1/2 x 4 =2)
> =18"
> ...



For A.) use the shrink chart for the lesser degree of bend on your 3-point saddles.

IE.
30/60/30 use the shrink amount for the 30
22/45/22 use the shrink amount for the 22

As big john said re-check E.)


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## Derek.bick (Sep 21, 2013)

A) 16" + 1"(30 degree angles shrinkage per inch of rise = 1/4", so 1/4 x 4 =1)
=17"

E) 118" (1/4=shrinkage per inch for 30 degree, 1/4 x 4 =1", so you would subtract 1" + 1" from 120" to give you 118").


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## Derek.bick (Sep 21, 2013)

So is that right? And can anyone help me with questions 2 and 3?


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## wildleg (Apr 12, 2009)

Derek.bick said:


> So is that right? And can anyone help me with questions 2 and 3?


what are the answers you came up with ?


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## Derek.bick (Sep 21, 2013)

I dont get how to do them.


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## Derek.bick (Sep 21, 2013)

Well for number 2 I got an answer of 55".


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## wildleg (Apr 12, 2009)

have you been listening in class ?

2 you just add the takeup

3 wants you to answer where your marks are for the bends to the saddle.

You need to try to figure it out. Go to the store and get some conduit. Come back with a real answer. You aren't trying.


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## Control Freak (Mar 8, 2008)

No you do not just add take up. You must subtract the gain. Rule of thumb is for shrink you add and gain you subtract. For example a whole stick of 3/4 tubing is 120". If you bend a 20" hook and add both sides you have more then 120". You will have 123" of total length . The 3" difference is the gain. Gain is usually half of the take up for that particular bender.


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## Control Freak (Mar 8, 2008)

I used to take the scraps on the job and and bend it up at lunch. Practice makes perfect. Eventually your boneyard will get smaller!


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## freeagnt54 (Aug 6, 2008)

Control Freak said:


> No you do not just add take up. You must subtract the gain. Rule of thumb is for shrink you add and gain you subtract. For example a whole stick of 3/4 tubing is 120". If you bend a 20" hook and add both sides you have more then 120". You will have 123" of total length . The 3" difference is the gain. Gain is usually half of the take up for that particular bender.


Well to get the answer for #2 you would add the gain, not subtract.


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## Control Freak (Mar 8, 2008)

freeagnt54 said:


> Well to get the answer for #2 you would add the gain, not subtract.


Correct. Normally Gain is used to determine the total length needed in order to cut the conduit and thread prior to bending. That why I said gain is usually subtracted and shrink is usually added. I wasn't clear in my response. I was simply trying to explain to the young apprentice that there were other aspects to consider. Thanks for pointing that out.


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## noarcflash (Sep 14, 2011)

They actually have school for EMT bending ????????? I brought 100' and a hickey, and graduated 2 hours later. :thumbup:


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## glen1971 (Oct 10, 2012)

noarcflash said:


> They actually have school for EMT bending ????????? I brought 100' and a hickey, and graduated 2 hours later. :thumbup:


I know we didn't get taught anything on conduit bending up here.. It was called on the job experience, with a J/Man showing me the ropes. How to bend 90s, offsets, saddles, etc.. Then how to layout racks with the least amount of crosses possible.. The tricks came later.. Then I found out that rigid conduit is a whole new learning, so that you don't spin yourself into a corner...


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