+++ PRESS RELEASE +++
Move forward by using metric
Elgin, IL, June 2014
Background
In machine and plant design, components like connectors are building blocks of connectivity. Engineers
combine these and other components to create cable sets that become part of complete machines or
processes. With trade increasingly global, the selection of components has to take into consideration
the needs of foreign as well as domestic customers and such issues as the recognition of local
standards, the management of production inventory and the timely availability of suitable replacement
parts. That clearly favors the greatest uniformity - even universality – of component sizes and standards.
A perfect example of the challenges and the trends is the different national units of measurement for
industrial wiring, cable glands and connector entries, and in particular, threading. Companies competing
in or contemplating an entry into global markets have to consider adopting a single unit of thread
management rather than maintain different ones for different markets. They have to consider not only
what foreign customers would prefer today, but what those customers believes they will need tomorrow
if they take charge of their own equipment maintenance. That’s also true if you supply sub-systems for
domestic OEMs who export. If you’re not thinking about their needs in that way, your competitors
probably are.
Today’s well known thread units are PG, NPT and Metric.
PG
Even though PG (Panzergewinde) size thread is a well known unit, it no longer has any recognized
validity. The 10-year transition period for the existing standards for PG threads, DIN 46320 and DIN
40430, ended in 1999. Panzergewinde sizes are named with the prefix PG plus a nominal number
which approximately corresponds to the maximum cable diameter (in millimeters) that can be passed
through the conduit. It has been a standard purely governing dimensions, but not quality and safety
aspects.
NPT
National Pipe Thread Taper (NPT) is a US standard for tapered threads that dates back to 1864 and is
used on threaded pipes and fittings. In contrast to straight threads found on a bolt, a taper thread will
pull tight and therefore make a fluid-tight seal. The origin of this NPT unit is based in fluid management
that also occurred in the area of electrical equipment, junction boxes and connectors.
Metric
The CENELEC European committee for electro-technical standards has developed a
standard for metric cable glands. The European standard, EN 50262 „Metric cable glands for electrical
installations” has been in force since 2000 and the complementary metric thread ISO „fine“ was
introduced for cable glands. The most important modification for cable glands has been to make it
specific to that class of product, covering relevant quality and safety issues.
Global view
Since the introduction of metric cable entries, the worldwide share for metric components has risen to
about 68%, including a 75% share in Europe where there is a strong history of metric standardization in
industry. Now, even Asia has passed the 50% threshold, driven mostly by a strong uptake in China. In
the Americas, PG (~65%) is still widely used. Nevertheless, there has been a strong trend towards
metric cable entries that began around 2005 as vendors and their customers began to appreciate the
importance of adopting an international standard for product design, manufacturing, marketing, and
Telephone +1 (847) 717-9217 | Christina.Chatfield@HARTING.com | www.HARTING-USA.com
HARTING North America | 1370 Bowes Road | Elgin, IL 60123 | USA
labeling. For many export-oriented manufacturers, metric adoption is essential for their success in the
global marketplace.
Benefits / Advantages using metric cable glands
While metric cable glands are the most widely used in global markets and the metric standard is likely
to become universal before long, there are other, practical benefits in making the switch to metric now.
For users in the electrical industry and electrical wholesalers, as the chart below shows, eight metric
sizes replace 10 PG sizes. That simplifies the choice in electrical design and reduces the stock OEMs
and MROs have to carry. Companies that stock parts at various locations around the world can
standardize with metric, so that suitable replacement parts always are available, often by local
purchase, where they are needed. Using metric in cable assembly also reduces the overall number of
electrical blueprints.
Things to consider
Being globally competitive means being locally adaptable. And it’s easier to be all things to all markets
by employing a uniform metric approach that happens to conforms with all local safety and electrical
standards and is in common usage. Many US manufacturers and their domestic customers already are
familiar with metric. Metric components are widely available in the US at competitive pricing and can be
incorporated into new equipment designs just as easily as NPT or PG supplies. Adopting HARTING
metric components opens up additional markets without sacrificing domestic competitiveness.
Media Contact:
Christina Chatfield,
Marketing Communications Manager
HARTING North America
1370 Bowes Road
Elgin, IL 60123
+1 (847) 717-9217
christina.chatfield@HARTING.com
www.harting-usa.com
Telephone +1 (847) 717-9217 | Christina.Chatfield@HARTING.com | www.HARTING-USA.com
HARTING North America | 1370 Bowes Road | Elgin, IL 60123 | USA