Vernier Caliper Shootout The selection of calipers under test. Left: sub £1 plastic Vernier caliper, centre: Mitutoyo 530-122 Vernier caliper, right: cheap digital caliper.

Along its shiny sides you'll find a four-inch Vernier caliper (with scales of 0.1mm and 1/16-inch), a metric screw-thread scale and a tire-tread depth-gauge. Press on the end and, of course, the ...