Page 195 - TesaKatalogen

L e ng t h a nd Ang l e S t a nd a r ds

PURCHASING GAUGE BLOCKS CALLS
FOR CONFIDENCE

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.

ISO 3650
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 (see "Which grade do you need").
–– Introduction of requirements as regards the uncertainty of measurement in relation to the declara-

tion of conformity of the product according to ISO 14253-1:1998.
–– Review of some definitions and shortened form of terms according to normative references that are

currently applicable (see drawing).

Which Material Do You Need?
Steel
Steel gauge blocks have proven their reliability for more than a hundred years. This raw material re-
mains the most commonly accepted for length standards.
Steel gauge blocks provide high resistance to wear associated with a good property to adhere to other
gauge blocks. However, steel must be protected against corrosion. Provided gauge blocks made from
this material are properly handled, they will remain reliable for many years. TESA steel gauge blocks
have the following key features:
–– Highly alloyed steel
–– Hardness guaranteed to 800 HV
–– Artificially aged for optimum form and dimensional stability
–– Coefficient of thermal expansion: (11,5 ± 1,0) x 10-6 K-1
Tungsten Carbide
Gauge blocks in tungsten carbide are 10 times as resistant to wear as steel gauges. They are intended
for frequent use, also where superior wringing quality is required. TESA tungsten carbide gauge blocks
provide:
–– Hardness guaranteed to 1400 HV
–– Coefficient of thermal expansion: (4,23 ± 0,1) x 10-6 K-1
Ceramic
Ceramic gauge blocks are extremely resistant to wear and scratches. Due to the properties of this ma-
terial, any minor damage is unlikely to affect the wringability of their measuring faces. Being corrosion
resistant, these gauge blocks are insensitive to "rusty hands", amongst other issues. Manufactured
from stabilised zirconia, TESA ceramic gauge blocks have the following key features:
–– Non-magnetizable
–– Hardness guaranteed to 1400 HV
–– Coefficient of thermal expansion: (9,7 ± 0,8) x 10-6 K-1

K-2