How Do I Cut Metal-Shielded Wiring?

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  #1  
Old 11-12-10, 01:13 PM
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How Do I Cut Metal-Shielded Wiring?

I've done some very basic stuff with the romex - and I'd just cut back the plastic; but I'm trying to add an outlet in the garage and I've got the shield stuff. Is there a trick or a tool I need?

Edit - I believe it is MC Armored cable - with the spiral metal armor.

And, well, just to double check; it is okay to have this metal stuff on the outside of drywall, correct? I probably should have done more research before starting this; but the Home Depot guy made it sounds so easy
 
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Old 11-12-10, 01:39 PM
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Originally Posted by RobDude View Post
Is there a trick or a tool I need?
There is a special rotary cutter that makes the job quicker, but for a small amount you can use a hacksaw carefully. Cut through the humped-up part of the spiral lengthwise with the cable. Unscrew the piece of spiral you just severed. If this is armored cable (AC) you will need to preserve the bonding strip to install in the box fitting for proper grounding to the metal box. Insert the red anti-short bushing to prevent the sharp metal from cutting the wire.

it is okay to have this metal stuff on the outside of drywall, correct?
Technically no, but many inspectors will accept this as sufficient protection in a residential garage.
 
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Old 11-12-10, 04:02 PM
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I've often just unwound a few inches of the armor and snipped it with diagonal cutting pliers. Is that bad? Wear gloves, lots of sharp edges.
 
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Old 11-12-10, 05:12 PM
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The instructions I learned and seldom mastered was to using a hacksaw cut at an angle oblique to the spiral part way through then snap it with a twisting motion but maybe that was only BX.

 

Last edited by ray2047; 11-12-10 at 05:36 PM.
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Old 11-12-10, 05:24 PM
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I am not a fan of using diagonal cutters due to how it mangles the metal jacket.
I only use a hacksaw at about a 20 degree angle to the cable. With MC you only need to go about 3/4 the way through a spiral, then twist the jacket and it will break.
 
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Old 11-12-10, 05:39 PM
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The angle in my post above is probably more then 20 but it gives the general idea.
 
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Old 11-12-10, 06:13 PM
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