I am .850" on joints and the butt will vary from 1.250" to a little over that. I have seen Meucci cues with as small as .780" joints and McDermotts with .890" joints. So there is no standard, but among stainless jointed cues they seem to have settled in at .830" to .840" with .840" being most popular.
Chris www.hightowercues.com www.internationalcuemakers.com