INSIDE MICROMETER CALIPER Inside calipers a r e used for internal work such a s bored and reamed holes and are made both in the spring and firm joint type. In setting the calipers to a scale, hold the scale against a flat surface, placing one leg against the flat surface and adjusting the other leg to the required dimension (105). If you are boring to ac - Inside micrometers (107) curate dimensions, set a micrometer to the dimension are manufactured for diameters of one - half inch and up. They are read the same a s outside micrometers. INS I DE CALIPERS required and transfer this to your inside caliper.
This can be done best by holding the micrometer in the left hand and the inside caliper in the right hand (106) and adjusting it until the proper " feel " i s obtained, The adjustment is obtained by rocking the caliper in a ver - tical plane between the axis of the anvil and spindle of the micrometer. When calipering a hole (108) set one leg of the inside micrometer caliper in the hole, pivoting the caliper in a vertical plane and adjusting until the other leg enters the hole. By rocking and adjusting the caliper, the proper " feel " across the largest diameter can be ob - tained.
If the calipers are forced into th e hole, the legs will spring and an inaccurate measurement will be ob - tained. When boring a hole to fit a shaft or turning a shaft to fit a hole, it is necessary to transfer measurement from outside to inside calipers and vice versa. This can best be done by holding the outside caliper in the left hand, supporting it between t he thumb and forefinger (109) with the second finger of the left hand supporting the lower legs of the outside and inside calipers to be set. The inside calipers are held in the right hand with the adjusting nut between the thumb and forefinger.
By rocking the inside caliper in a vertical plane and ad - justing it until the proper " feel " i s obtained, accurate transfer from one to the other can be made. Do not use for exact measuring.