Yeah very handy to be able to work around it, mine is on a pole in the slab, bout 3" from memory and the pipe is full of concrete as well, still vibrates a bit unfortunately when hack sawing.Mounted to a really heavy bench, would love to have one mounted on a stand by itself, right into the floor. Would give a lot of flexibility with it.
The leg vice is my favorite. Had one for years until the threading on the tube disintegrated. Bought a 7 inch Wilton but it's not the same. Those old vices could be hammered on and didn't crack. The spring give up and I replaced it with a buggy seat spring. Any vice you do buy today I suggest you get one that has provisions for holding tubular objects. Whether you are fixing rams, working on shafts or pipe; a pipe holding vice is handy.I think this was old when my Dad bought the farm 53 years ago.The bench it's on is attached to the shed wall.The post behind the vice goes through the wood floor into the dirt underneath,it's pinned to the post with a large nail on either side of the steel rod.It has seen a lot of hard use and never broken loose.