He sould use an anchor that expands in the hollow part of the block.
You are correct, the Tap-Con (the blue screw) can pull out of the soft thin
outer surface of the block.

"marc rosen" wrote in message
oups.com...
Hello Group,
I was helping my nephew mount his kitchen cabinets on a block wall that
has a 1/2 inch plaster finish. He is using those blue masonry lag
screws to hold the units up. I have only used these screws in solid
caps or solid concrete, never in blocks. The screws only have the
thickness of the block wall (not certain how much that is)for thread
contact, not the entire threaded portion.
He is only using four screws per unit but I suggest six.
Who out there has used these screws in block walls and what are your
recommendations?
Thanks in advance for your responses
Marc