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I only have a Dewalt Atomic 20V Hammer Drill and need to drill a concrete wall that is 6 inches thick. It is mostly concrete cinder blocks and some rebar. I need to pass some electrical cables and want to use a 1-1/4 inch PVC Schedule 80 electrical conduit. On both sides I have a 6x6 inch PVC junction box to cover the holes and cables. The largest drill bit I have for concrete is 7/8 but only 4 inches long.

The closest tool rental shop only has a 2 inch core drill bit and with the drill is about $85 a day.

Since I will cover the hole (or holes) with the junction box I was thinking either make a few 3/4 inches holes for the wires (about 8 RHH 10 AWG) or buy a cheap core bit that might work with my drill.

Would like some suggestions.

Rick151
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You haven't mentioned a geography but I'll assume that NEC rules apply. Passing individual conductors through individual holes won't fly: plain conductors are required to be inside a conduit, and all the conductors pertaining to a circuit (the hot(s) and neutral) are required to be in the same conduit.

PVC 1-1/4 conduit is nominally 1.66 inch outside diameter so a 2 inch core hole really is the right size for that job.

If your wall is truly only concrete block and the cells of the block are not filled with concrete/grout then you have more options. You could perforate the perimeter of a 2" circle with whatever drill bits you have at hand and then use a chisel to "connect the dots" and break out the center. A hand chisel wouldn't be a terrible way to do this, but there are a variety of power-driven chiseling solutions too.

Greg Hill
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