I've only used the hanging rail when installing some Ikea cabinets. I thought it was a pretty good system even with the non-adjustable brackets. The Hafele hardware is much better.
Checked into using hanging rails in NA and there are lots of the usual reasons not to bother but here is a good explanation why it is good.
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If you use a recessed back, you gain the advantage of being able to use a hanging rail system for fastening the cabinets to the wall. I have been using the Camar system for 6 years or so with no problems – just solutions. The hanging rail is so easy, so exact that I’m surprised it hasn’t come up in this discussion.
The concept is this:
1. Install a hanging bracket in the top right and left corners of the box. I do the boring for this with a simple jig when the cabinet sides are flat on the bench.
2. Install the hanging rail at desired height. 1 5/8” from top of cabinet works best for me. Fasten to studs, and use toggle bolts between studs. I cut the hanging rails in the shop and mark cabinet locations on them (a story pole for the installation).
3. Once rails are secure, lift the boxes onto them, slide into position and level using the adjusting screws on the hanger brackets. Once I have the cabinets close, I fasten them together, double check everything, then tighten the whole run of cabinets to the wall.
I realize that this adds another setup to your cabinets. One more thing to do. Why? How many times have you put a screw into a cabinet that missed the stud, or had a cabinet that ended up with only one screw supporting its weight? How many times have you sent two guys to the install so one can hold the cabinet while the other is screwing? Or how about those times that the cabinets move just a bit as you tighten them up, and you have to try and adjust, but don’t want that extra screw showing inside?
This is something that can take place in the shop with simple jigs. Once on site, I can hang an entire run of uppers by myself. I can get every cabinet dead level, plumb and square with a screwdriver once they are on the wall. Cabinets can be taken down easily to scribe, then put back in place and adjusted to perfection – taken back off and put up again – no changes to adjustments. And it’s strong! I’m over 230 lbs, and I hang off of every run as a final check.
With that in mind, we use 1/4” cabinet backs and dado into the side to leave 1/2” of space behind the back to the wall. This accommodates the hanging system. We rip our tops 3/4” smaller that the bottoms and sides (11 7/8” sides and bottoms, 11 1/8” tops). This allows for inserting the cabinet back into the finished box, and also allows for the hanging rail to be continuous along the cabinet run."
- See more at:
http://www.woodweb.com/knowledge_base/Recessed_or_flush_cabinet_backs.html#sthash.v0ms5dVX.dpuf"