Electrician’s use a Box Offset bend anytime they need to feed an electrical box with conduit. it is one of the more basic bend they make just about every day of the week. I’ll step you though how to make one.
Hi folks it’s Ron with IDEAL.
In this video I will show you one way to make a Box Offset Bend in a ½ inch EMT conduit using a hand conduit bender from IDEAL.
A Box Offset Bend is needed anytime an electrician needs to feed an electrical box with a piece of conduit. The knockout on the electrical box is not flush with the back of the box hence the conduit must be bent slightly so it can be inserted into the conduit fitting attached to the box. This allows the conduit to be mounted properly to the wall without putting undue stress on the conduit fitting.
For this demonstration I will use our catalog number 74 – 026 Ductile iron head bender from IDEAL. The ductile iron head benders are typically preferred by the professionals as they will last longer than aluminum bender heads which are lighter weight but less durable.
Generally a 10° offset Bend is used to create this box offset. If you remember my video on offset bends a certain shrink amount and a multiplier is used to create the offset.
On 10° offset bends the shrink amount is 1/16 of an inch for every inch of obstruction and the multiplier is six which is used to calculate the distance between the two bends I need to make.
On a typical electrical box the knockout is about 3/8 of an inch away from the back of the box which becomes the height of the obstruction we need to overcome. Six times 3/8” is 2 ¼” which becomes the distance between the two bends on the conduit I will make. The shrink amount is so small it is not a factor.
To make the box offset on the end of a piece of conduit I will make two marks.
Step one is to make the 1st mark at about 2 ½ inches from the end of the conduit. If I make the mark any closer to the end of the conduit the hook of the bender head may deform the round shape of the end of the conduit and not fit inside the conduit fitting on the box.
Contractors generally use a pencil to mark the conduit so it can be erased later. In my example I will use a permanent marker and mark the conduit all the way around so the mark will not get lost in the conduit head when bending.
For the 3/8” offset we calculated the distance between bends to be 2 ¼ inches. So I’ll make a second mark 2 ¼” away from the first mark and mark the conduit all the way around.
Offset bends are done in the air not on the ground. Simply stand the bender with the handle pointing down and bender head closer to you.
Step two is to insert the conduit into the bender head and lineup the first mark with the arrow on the bender head. Bend your knees to lower your center of gravity and place 1 foot up against the bender handle to keep it from slipping. Then using constant pressure close to the bender head, bend the conduit to the 10° mark. The bottom of the conduit will be even with the mark.
Step three is to slide the conduit down to the second mark and line it up with the arrow on the bender head. Rotate the conduit 180° and align the first bend with the second bend sighting down the bender handle. Then bend the conduit to 10° again.
This creates the box offset in the conduit that allows it to easily slide into the conduit fitting on the box.
Knowing how to make a box offset bend quickly and efficiently will make those jobs run that much smoother and add value to what you can do.
Electricians don’t bend the conduit and then cut it to the correct length. Once they know how to use a bender correctly the conduit is the correct length for the job. Using a good quality hand conduit bender like this one from IDEAL will provide accurate and professional looking bends that electricians expect while on the job.
If you want to learn more about the line of hand conduit benders from IDEAL. Please visit our website or contact our customer service department to find a local distributor.
Thanks for watching folks I’m Ron with IDEAL and see you on the next one.