FALL 2016

8
THE DISTRIBUTOR’S LINK
Bengt Blendulf
Bengt Blendulf was educated in Sweden and moved to the US in 1974 to start a subsidiary for a Swedish fastener
manufacturer. After working as a technical consultant on the faculty of the College of Engineering and Science at
Clemson University, he established EduPro US in 1997 to teach highly rated courses in Fastening Technology in the US,
Canada, Mexico, Europe and Asia. Being one of the founders, Bengt served as the chairman of ASTM F16.96 Bolting
Technology from 1996 to 2006. In 2006 he received the Fred F. Weingruber award from ASTM for “his efforts to promote
and develop standards for the fastener industry.” In 2013 he also received IFI’s Soaring Eagle Award for “significant
contributions to the technological advancement of the fastener industry”. Bengt is the author of an extensive lecture book,
well over 110 articles and “Mechanical Fastening and Joining”, a book published in 2013 by the Industrial Fasteners
Institute. He can be contacted through www.edupro.us or by email bblendulf@yahoo.com.
SHARING TECHNICAL INFORMATION
ABOUT FASTENER USE
Having written many articles related to fasteners
and their use (125 now!) for 35 years in the Distributor’s
Link Magazine, I just took a look back at the list of titles
of these articles. The first 10 years, about half of the
articles I wrote were dedicated to metric fasteners and
SI metric terminology starting back in 1979. Gradually,
the topics I have chosen have changed to include more
and more information about more technical aspects like
the design of the bolted/screwed joint and many related
things. Why is that?
First of all, there are today over 50 percent metric
fasteners used by the US manufacturing industries.
This is a tremendous change from the 1970’s and is
mainly due to the internationalization of our trade. A lot
of US manufacturing has been going overseas and those
“new” countries being metric already, made the choice
easy and has had the effect of change in our domestic
usage as well. Big metric volumes are accounted for by
our automotive and electronics sectors, but also smaller
companies have joined in the conversion to metric. This
is mainly due to the fact that if we are exporting we have
to look at the convenience of service, access to parts
and local competition. This is now also true for those
foreign industries (Volvo, VW, Toyota, Honda, Nissan,
Mercedes and others) who are now manufacturing their
products here in the US. For example, Volvo was entirely
based on the inch/pound system even back in the
1970’s due to service convenience at the major market
place = United States. But, when the US automotive
sector went metric, a total re-design of Volvo autos to
metric took place quickly. For Volvo, this was a relatively
CONTRIBUTOR ARTICLE
easy task being a part of a country (Sweden) that had
been metric for many years. And fasteners and other
products were readily available which helped a lot.
But their cars had a relatively long life span, meaning
double inventories of fasteners over many years. This
is also the case for many US industries being forced
to maintain both systems. Take the farming equipment
manufacturers (now predominantly metric) who have
converted to metric for all new models. But, they still
have to maintain older tractors and harvest machinery
being put together by inch fasteners.
So, the change-over to metric is an ongoing,
and sometimes rather painful, exercise. I wish that
this process was easy and quick, but it is not. We
have too many players (ASME, ISO, ASTM, DIN, SAE,
IFI, JIS) working on the same standard issues, but
not always the same way. This dilemma has been
recognized, fortunately, by some technical leaders like
Joe Greenslade from IFI, who have consistently tried to
simplify the fastener standards for us. Joe and I had
always maintained the idea about using ISO standards
and scrapping all old national metric standards. He
managed to change some duplicates and make things
easier for the US user industries. Whether we will follow
his lead or just keep tramping on in the more familiar
tracks will be seen.
Who needs technical information about the use of
fasteners? Judging from the attendance in my classes –
everyone who is working with the design and assembly
of the bolted/screwed joint needs more and better
information.
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