I find myself setting up smallish parts in the mill vice where I'm drilling through or slotting through and therefore cant have the parallel contacting the underside of part in the break-through area. I'm talking narrow-ish width parts with a single parallel setup or using 2 parallels on either jaw but insufficient clearance for drill to clear between them. If I use my standard 6" parallels with a gap in the middle, it works, but they usually overhang my (4-5" width) vice bed on either side...
Half Length Parallels?
Half Length Parallels?