SPRING 2022

8
THE DISTRIBUTOR’S LINK
Laurence Claus
Laurence Claus is the President of NNi Training and Consulting, Inc. He has 25 years of
experience with a medium sized automotive fastener manufacturer, holding positions
including Vice President of Engineering, General Manager, Director of Quality, Director
of New Business Development and Applications Engineer. In 2012 he formed NNi
offering technical and business training courses as well as technical consulting, expert
witness and consultation work. He can be reached at 847-867-7363 or by email:
Lclaus@NNiTraining.com. You can learn more about NNi at www.NNiTraining.com.
HOT FORGING FASTENERS
My first job in manufacturing was in a General Motors
sheet metal stamping plant. We made quarter panels,
fenders, doors, roofs, and many smaller components that
are married with others to build an automobile’s body.
The scale of this plant was huge and everything appeared
to be on steroids. The stamping presses could stand
over five stories tall and handle a die the size of a VW
Beetle but many times heavier. It was exciting every time
I stepped onto the plant floor and instilled in me a lifelong
appreciation, curiosity, and respect for the way things are
made.
Fast forward a couple of year and I recall my first time
observing how average size screws and bolts were made.
Honestly I was in awe at the speed and ingenuity of cold
heading and thread rolling, and, although I would spend
nearly every work day of the next twenty-six years in close
proximity to these same headers and rollers, I have never
lost my appreciation for the process. In those early years,
though, I often wondered what process is used to make
really large fasteners or fasteners from difficult to form
metals.
My question would eventually be answered when I
received an invitation from a fellow Industrial Fasteners
Institute member to come and visit their hot forming
facility. Once again, my eyes were opened to a new and
different way of making fasteners. If you have never had
the opportunity to see this process firsthand my hope is
that this article will serve as a journey into the basics of
hot forming fasteners. This article will explore basics of
the process, explain when it makes sense, and several
different approaches commonly used to hot form parts.
TECHNICAL ARTICLE
FIGURE 1: HEATED RAW MATERIAL ENTERING A HIGH SPEED
HOT FORGING MACHINE
What Is Hot Forming?
One doesn’t have to be in the industry long before
encountering terms like cold forming, warm forming,
and hot forming. It is clearly understood that these are
uniquely different processes, but what is the difference?
Obviously the answer to this question is the temperature.
It is universally understood that adding heat to metals
makes them easier to work. Therefore, if you have to
form a shape that is any more complex than a cylinder
or rectangle, adding heat probably makes the job easier.
Of course adding heat also complicates things. It makes
parts harder to handle, adds safety concerns and risks,
complicates processing equipment, and, if not carefully
controlled can change the physical composition of a part.
This list of concerns causes manufacturers to walk a fine
line and not complicate their processes by adding heat
unless it is deemed necessary.
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