If your goal is to have dynamic o-ring seals according to engineering standards, make sure that your cylinder, when bored and honed, will finish at 0.750. O-ring actual O.D. size is slightly larger than theLockednloaded wrote:Jrrdw, I was planning on sending the 3/4" nipple to him as well.
o-ring "nominal size" for a good reason. When placed on a piston with ring glands machined to the proper size and shape, the o-rings have the proper amount of "squeeze" to form a dynamic, high pressure seal.