On Thu, 15 Mar 2012 15:20:36 -0700, PrecisionmachinisT wrote:

"jim" wrote in message
...


If a thin wall is a problem then it's usually better to first bore the
cylinder to an undersize condition and slot the ports using whatever
convenient means is available, finally finishing the cylinder bore by
holding from the part outside diameter in a collet or some type of full
grip vise jaw type of fixturing device.

That's exactly what I intend to do -- the last thing I want to do is go
hacking at the holes when I don't have enough meat in the cylinder liner
to correct any problems.

holes with square sharp corners


Does not exist--the best you can do is to approximate by specifying the
max allowable mismatch and corner radii.

I just want something that's significantly more square than it is round.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com