In the quest for ever greater sustainability,
manufacturing companies are looking to make
savings every which way without compromising
quality. Cold forming is a metal manufacturing
process that not only cuts waste but improves the
integrity of component parts, says Mark Jennings,
engineering director at Dawson Shanahan

Metalworking can produce a lot of
waste material. For example, many
metal manufacturing processes
generate considerable volumes of waste
metal in the form of swarf, chips and offcuts.

In fact, the manufacture of many
components that are cut, milled or ground
from solid workpieces can result in 80% or
more of the original material being
converted to waste.

With environmental legislation rising high
on the agenda and an increasingly discerning
customer base when it comes to
sustainability, manufacturing companies
should consider the significant cost
reductions that can be brought by cold
forming, especially since they bring benefits
that are not only ecological but financial.

The best way to start when cutting back on
waste and inefficiency is to go for the largest
targets and attacking that 80% of waste metal
is a good place to start.

Modern CNC machine tools are highly
sophisticated and extremely accurate but can
create considerable waste, regardless of the
skill of the machine operator. This mountain
of scrap has to be recycled, often at a cost
both to the company and the environment,
leading to higher part costs for the end user.

Producing parts via cold forming can
often provide a more cost-effective solution.

Even where conventional machining remains
the best solution, there are many
opportunities to combine precision cold
forming with CNC machining. This can
reduce the size of the initial blank of metal
by 75% and scrap volumes by up to 90%.

Cold forming can now be used to shape a
wide range of metals, including copper,
brass, aluminium, steel and even stainless
steel. In addition to the attractive cost
savings that can be achieved, precision cold
forming can actually enhance the material
properties of the metal. In fact, cold forming
using oxygen-free copper produces better
results than machining in many applications.

This is because its electrical and thermal
properties result in components with, for
example, highly polished surface finishes.

Another advantage of adopting cold forming
is that parts produced using this process can
be fashioned with highly complex
geometries. Indeed, complex internal shapes
that would be almost impossible using some
traditional machining can easily be produced
using the cold forming process.

One indirect but nevertheless significant
way in which cold forming reduces waste is
that the strength of the metal itself is
increased as a result of the cold forming
process, resulting in tough, long-lasting end
products. In cold forming, a simple blank,
which has been sawn or cropped from a
round bar or wire, is placed within a cold
forming press, where die and punch tooling
is used to extrude the metal under extreme
pressure. The metal is stretched beyond its
yield strength but without adversely affecting
its tensile strength. As a result, the strength
of the part is maximised along its length, in
much the same way that a sawn piece of
timber is stronger along the length of the
grain. Parts effectively undergo work
hardening during the extrusion process,
improving their machinability and durability
still further. What’s more, the benefits of
precision cold forming described above are
consistent with all types of metal, even
stainless steel.

Industry at large is becoming more
responsible, which means that efficient and
sustainable processes are increasingly
important. Cold forming delivers improved
quality as well as high levels of
manufacturing efficiency, proving that
reviewing, evaluating and implementing
advanced production processes can benefit
plant performance, improve output and
target sustainability.