The two main uses for the v-anvil micrometer are measuring the outside diameter of a cutting tool that is built with an odd number of flutes (typically three or five) and measuring out-of-roundness on the exterior of a part. In measuring diameter on a cutting tool with an odd number of flutes, the v-anvil micrometer is designed to account for the off placement of the surfaces used for measurement. In order to complete this measurement, you lay the cutting tool on its side, perpendicular to and across the “V” anvil. Once the lanes of the flutes are lined up with the side surfaces of the anvil, put the spindle into place using the ratchet and you are good to go. When measuring out-of-roundness, the v-anvil micrometer creates the optimal spacing to accomplish this task. After measuring multiple points along the outer surface of a part, subtract the smallest measurement from the largest and divide the resulting number by two. This provides you with a measurement of out-of-roundness. V-anvil micrometers can also be used to apply the single-wire method to measure the pitch diameter of a smaller tap.