1) For cinder block walls, I prefer to use 4" toggle bolts, 3/8" diameter. You may need to insert a washer onto the toggle bolt head prior to inserting into the Unistrut hole. Often the holes on the Unistrut will be too large for the toggle bolt head.
2) I would recommend using a quantity of (4) four toggles. One near each end and then space the other two accordingly.
3) EMT needs to be supported within 3 ft of any box and supported a maximum of 10 ft from support to support.
4) You will also require the Unistrut pipe clamps to secure the EMT to the Unistrut.
5) Tapcons are another option. These are threaded anchors with a hex head and can be driven into concrete using a drill with a hex head attachment. If using Tapcons, you will need to drill out the hole accordingly and use the correct drill bit. Too large of a hole and the Tapcons will not bite into the concrete. You will also need to use washers if using Tapcons. Tapcons will hold better if secured to the middle portion (solid) of a cinder block. I have used a combo of toggles and Tapcons but I usually use just toggles.
6) When installing the EMT, suggest installing the EMT as much as possible near the center of the Unistrut. Installing it this way will keep the unistrut ends open and available for any future EMT attachment to the unistrut.
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