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Bending Conduit (EMT)

16K views 56 replies 27 participants last post by  Cherry Hill Bill  
#1 ·
Some time ago I had a JW teach me a way to bend conduit. It was not the typical Bendfield's technique. He would make a bend, lay it down on a flat surface, and measure the second bend for the offset. Does this sound familiar to any of you master benders out there? I just wanted to refresh this in my skills but just can't seem to remember the steps to do it. Any help would be appreciated!
 
#3 ·
I see guys using this trick all the time. You just make your first bend, stick the conduit against the wall or another unbent piece of conduit and measure after the bend until you find the distance you want, pencil it, line up the appropriate mark on the bender and make the next bend.

I like using the iBend Pipe app, or the regular multipliers more than this trick though.
 
#4 ·
I know the "normal" way is to use your offset distance with the multiplier and make both marks, then bend but this was a different way...not really sure if it was better or worse. Just remember that you could bend any degree offset and not have to memorize the tables. Let me know if you see something maybe out of the ordinary in the Cox book. Thanks!
 
#11 ·
Ya use 30's when u can but the method the op is speaking of comes in very handy. I know my other multipliers but I use this method often when I need 45 or something other than 30. You cannot use it for over 45 remember.

You make the 1st bend at the pt. Like ya'll said....if it's a 10 inch offset. Ya lay your pipe with the one bend in it next to a straight piece and measure from the straight one down to the bent piece....mark the spot for the 2nd bend and presto.

Ya may have to tweak it some. Remember a multiplier for 45's is what 1.416 or something so unless your using that in your method you would have to tweak it some anyway.

Folks are so quick to discount a way they don't use. Use BOTH methods BOTH when appropriate. I had a foreman bitch at me cause I didn't use this method all the time. Ridiculous. 30's x 2 most of the time and this 'trig' method once in a while when needed.
 
#17 ·
An offset is 2 measurments. 1st is the point=at what point does the obstruction occur. Lets say 12". Ya mark the pipe at 12" (with a big fat sharpie of course)

The 2nd # is the actual offset=how far does your pipe have to move in space to avoid the obstruction. Lets say 10".

30 degree bends won't do ya need a sharper angle so ya go with the trig method.

Ya put the bender on the hash mark on most benders. I don't think that's even gonna matter much as long as you use the same mark both times. Put it right on the 1st mark ya made on the pipe (your point mark).

Pull a 45 or whatever. Doesn't need to be precise most of the time. Your gonna pull past the 30 mark and stop before the 45 mark.

Take the pipe outa the bender. Lay pipe flat on the ground. Lay a straight piece right up against it on the ground. Now ya got a nice little trig triangle thing going right?

The straight piece of pipe at the top and the angled piece below that or closer to you...

Take your tape measure and butt it up against that straight piece. Measure down 10" and mark the angled piece of pipe at the point where 10" meets your angled pipe coming from your straight pipe. Too far left it will be less than 10"...no good. Too far right it will be more than 10"...no good. So your tape measure has to be at a 90 degree angle coming from that straight piece or you'll throw your measurement off. Mark it...spin it...make the 2nd bend. This time just use your level to get the angle the same.

Now...go throw it in the dumpster and try again...you'll get it...
 
#21 · (Edited)
Why do people say there are charts to memorize? Just memorize the formula. You should already have a calculator handy.

1/(sin of angle) x (amount of offset) = distance between bends

Where these charts come in to play, I'm not sure





The only time you should use that trick is if you need a really rough measurement... "I need about a foot of offset. Anywhere from 10" to 26" should be fine." If you are using that method for everything than you are a hack and should go back to being an apprentice so you can learn how to do things correctly.
 
#45 ·
Why do people say there are charts to memorize? Just memorize the formula. You should already have a calculator handy.

1/(sin of angle) x (amount of offset) = distance between bends

Where these charts come in to play, I'm not sure
The charts are for those of us who do not carry calculators. Most of the time they are unneeded but when you wander away from 15, 22.5, 30 and 45 they come in handy.
 
#23 · (Edited)
jimmy21 said:
Why do people say there are charts to memorize? Just memorize the formula. You should already have a calculator handy.

1/(sin of angle) x (amount of offset) = distance between bends

Where these charts come in to play, I'm not sure

The only time you should use that trick is if you need a really rough measurement... "I need about a foot of offset. Anywhere from 10" to 26" should be fine." If you are using that method for everything than you are a hack and should go back to being an apprentice so you can learn how to do things correctly.
Dido
 
#27 ·
if you are using a bubble level and you want to get that pipe in fast, nice-looking, and matching the existing installed conduits that someone else may have installed nearby then use the common angles
-----IIRC-----
7* - 8
8* - 7
10* - 5.5
30* - 2 <---- ON BUBBLE LEVEL, MOST COMMON
45* - 1.414 <----- ON BUBBLE LEVEL, LESS COMMON
60* - 1.15


for a 12" offset you place the lines 24" apart if you are using a 30* angle. There are situations where using the common multipliers just won't work, but unless there is a really pressing reason not to use the common multiplier it's best practice just to use the common angles.
 
#28 · (Edited)
For accuracy, you can use the strait edge method to check your first bend.

Explained: Lay out and make both marks for offset on pipe. Make first bend. Lay pipe against a strait edge. Measure from strait edge to second mark. If this distance is less than the needed offset, add more bend to first bend. If measurement is too much, take a little out.

Multipliers or a calculator are your friends for accurate bends.
 
#29 ·
All of the advice on bending with proper measurements aside...

This method requires you to know the center of bend on your bender. In most cases it is something like a star or a heart mark on the bender. Sometimes you need to work it out yourself.

Anyway the method works like this.

Bend your first bend.

Lay down the conduit, and using a straight edge ( another pipe ) on the bent end of the conduit, measure the amount of offset you want. The trick is to keep your ruler square to the straight edge and to measure and mark the bottom of the bent piece of pipe.

Once you have your mark, set that mark on your center of bend on the bender and bend until the offset is parallel.

I normally use proper bending methods but there is a time for every tool in the bag...I just don't bring this one out very often.

Enjoy
 
#34 ·
I use both methods just depending on the situation and which way I feel like using.However if I remember correctly it seems that the multiplier method goes from top of pipe to top of pipe and the straight edge method is the overall (top to bottom)The area where I'm at now(residential) mainly just bending 1/2 and 3/4 emt and can tweak it pretty easy for an accurate fit.