Conduit bending

[The electron man]

When bending conduit I don't understand were do I add the shink between bends ? Like if I'm make a 3in offset with 30° bends my bends are 6 and 3/4 apart since the shrink is 1/4" for every inch of rise ?

 

[infinity]

I'm make a 3in offset with 30° bends my bends are 6 and 3/4 apart since the shrink is 1/4" for every inch of rise ?

If you make two 30° bends 6" apart you will end up with a 3" offset. If you make your bends 6 ¾" apart you'll end up with a 3 3/8" offset.

 

[The electron man]

If you make two 30° bends 6" apart you will end up with a 3" offset. If you make your bends 6 ¾" apart you'll end up with a 3 3/8" offset.

So were do I add the shrink

 

[don_resqcapt19]

So were do I add the shrink

Shrink is the difference in length between the straight length of conduit and the length of the conduit after you have bent the offset. Unless the overall length required for the piece with the offset is too short to cut and thread after you have bent the offset, you don't need to do anything with the shrink.
If it the needed length is too short to cut and thread after bending the set, you add the shrink to the needed length, cut and thread the conduit, and then bend the offset.

 

[acin]

I got 10 sticks of EMT and spent the weekend bending different conditions along with a book and u tube clips , had a good time

 

[Crash117]

The shrink affects the overall length of the conduit you are working with, not the bend. Say you start with a 4’ (48”)length of conduit and bend a 4” offset with 30 degree bends. Your bend multiplier of 2 puts your bends 8” apart. Then with a 1/4” shrink per inch of offset, your final conduit length will be 47” as you are losing a 1/4” of conduit length per inch of offset. I tend to use 30 degree most frequently as the simple 2x multiplier is easiest to work with plus with the Ideal EMT bender, make a 30 degree bends means pulling the handle to vertical to make a 30 degree bend. It’s the quickest method to do offsets and most accurate without using any extra tools.

 

[Crash117]

Shrink will come into play in the following type of situation. Say you’re adding the next length of conduit. From the end of that conduit, there is a 4” obstruction from the end of that conduit that is 4’ away. You have to add the shrinking amount to the placement of your bends on this next conduit. At 30 degree bends with 1/4” shrink per inch of offset your first bend needs to be moved forward to 49”, then from that point take 8” back for your second bend. This way, once your bends are made, right at the 48” point where your obstruction is standing 4” high, your conduit will land perfectly on the obstruction.