FEATURES
Master vernier caliper has the virtues of both screwed verniercalipers and monoblock vernier caliper,but without theirshortcomings,because the left part and right part of its verniers areunmovable monoblock,but the middle part of its vernier is screwedvernier.
The jet black straight grooves on both sides of the master bar allowfor positive alignment of graduations and flush fitting of the vernierscales to the main scale,which eliminates parallax.
Can measure outside diameter(O.D),inside diameter (I.D),depth and steps