This item is great for setting up your mill. Aligns side to side and fore and Aft simultaneously. Then it keeps the adjustment fixed (without moving) while you tighten up the headstock
I once was using a square to align the head, the square slipped and the entire z column came down and dented the bed
The Nano-Tram Base works on most bench top mills and straddles most bench-top mill accessories. This tool is precision ground flat and parallel to .0003" over entire surface and is made from C1020 HR steel.
Inside dimensions for Nano-Tram Base are 6.44" between legs x 3.9" underneath gaging surface x 4.0" wide. Material thickness is .375".
The Nano-Tram top is 3.45" in diameter with a .250" diameter shank that is .90" long. Overall height of the tool is 1.375". Shank is perpendicular to the face within .0003". Material is 6061-T6 aluminum, hard black anodize.