The high accuracy of TESA's gauge blocks is the result of years of experience in producing and making use of these products.
� Use of high quality raw materials and appropriate heat treatment, thus guaranteeing a durable shape and dimensional stability of the gauge blocks over years.
� Very low deviations in flatness and parallelism of the measuring faces, resulting in highly accurate gauges.
� Unique flat lapping polish as well as edge rounding techniques, leading to superior wringability.
� Proper serial number marked on each gauge block.
Gauge blocks with metric nominal lengths conform to ISO 3650:1998. This international standard is based on the ones published either in a region, e.g. the European standard EN ISO 3650:1998 or in a country, e.g. the Swiss standard SN EN ISO 3650, German standard DIN EN ISO 3650 or French standard NF EN ISO 3650. Gauge blocks with imperial nominal lengths comply with BS 4311 - Part 1. Compared to earlier standards, ISO 3650:1998 includes the following main changes:
� Withdrawal of the accuracy grade 00
� Introduction of requirements as regards the uncertainty of measurement in relation to the declaration of conformance of the product according to ISO 14253-1:1998.