Over the Bar Micrometer OBM-4510

The simple solution to large bore measurement. This tool measures the bore without having to remove the boring bar, measuring from wall to wall giving you the same dimensions as an inside micrometre and accurate to thousandths of an inch. Comes complete with body, extension rods and adjustable micrometre in a fitted case.

Measurement range 4.5″ to 11″ (115MM-280MM)