This series is used to correct micrometer instrumental errors, spindle screw feed errors (example 1), and the parallelism and plane for each 1/4 rotation of spindles and anvils (example 2). The pin gauges have heat-insulation handles, which prevent body heat from affecting performance and can be used in-house to calibrate micrometers and calipers in order to acquire and maintain ISO-9000 accreditation.