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It all started in 1945 when Knud Hagens, engineer, -
my father – decided to open his own bicycle repair shop including a mechanical
workshop in a basement, where in the back room, he manufactured springs in thin
wire.
Many initiatives since then has
taken place and today we manufacture our springs in environmentally desirable
plants in Brovst and Støvring. Are deliveries from Støvring includes a.o. very
small and very powerful springs for the industry both domestic and abroad –
including the extension springs mentioned in this booklet.
The management is sited in Støvring.
Directors and managers of this company are now second
generation with a professional board and a staff of 100 skilled employees, many
of whom have several years of experience within this trade.
With flexibility, high quality, modern production
facilities and services in the form of spring design, we are sure that we can
meet your requirements.
Best regards
Peter Hagens
Materials
In order to meet the requirements of our customers, we
stock materials of various dimensions and qualities. All our suppliers are
reputable, supplying only materials made of the very best rolled wire. Thus we
ensure a uniform production and a high quality end product.
We are pleased to supply material specifications
together with the springs to the extent this is required.
Wire is produced
according to laid down standards. This applies to the alloys, the ultimate
strengths, the wire diameter as well as the production limits of the springs.
Mainly we make use of the DIN-standards including the
EN- and the ISO-standards.
Spring wire has to be very elastic when in use. The
limit of elasticity being very high, the limit of deformation becomes the
highest possible. However, when the limit of elasticity is exceeded – which is
necessary during the manufacturing process of springs – the deformability of
spring wire also has to remain sufficiently high.
Most springs are made of spring wire, which is carbon
steel, holding a C-content of
0.5-1.2%, varying according to strength. By means of a special hardening
process called patenting, then followed by drawing, ultimate strengths of
approximately 3,000n/mm2
are obtainable.
The mostly used patented spring wire,
is graded according to strength measured in DIN 17223-1:
DIN 17223-1, D and C Highest
ultimate loads Being used for all kinds of especially high stressed springs
DIN 17223-1, B Medium
ultimate loads Especially used for compression springs, torsion springs,
special springs, etc.
DIN 17223-1, A Lowest
ultimate loads Used for
extension springs, the low strength and high deformability being an advantage
to the working out of the loop. Furthermore, it is being used for spring rings,
wire forms and other kinds of wire shapes, etc.
Additionally
we have oil-hardened wire DIN 17223-2 which is characterised by a high
ductility and extremely good deformability, and special
Many springs are made of
stainless materials DIN 17224. Stainless qualities like 18/8 according to
Werkstoff no 1.4310, alternatively Werkstoff no 1.4401 being the most common.
However, if saline resistant or non-magnetic springs are required, we use hard
drawn bronze wire holding approximately 7% Sn.
Moreover, beryllium copper
wire, especially requested by the electrical and electronic industry, ought to
be mentioned. Here the characteristics of this material will do justice to
itself.
Springs are also made of brass, copper, aluminium,
German silver, etc.
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In the cross section of a compression spring the dispersion of the
shear stresses is irregular. The stresses of the inside of the coils are higher
than the stresses of the outside of the coils.
The correction factor k, used when checking the load, takes this into
account.
The correction factor k is dependent of the diameterindex D/d and
appears in the diagram below:
Compression springs are manufactured with different ends, and the
following drawings show this:
XXX XXX XXX
A: Ends not closed and unground
B: Ends closed and unground
C: Ends closed and ground
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The following diagram shows a compression spring with ends closed and
ground.
Compression springs are manufactured with ends closed or not closed,
and with ends ground or unground.
Usually, springs with a wire diameter under 1,0 mm are manufactured with
ends unground. This is also the case where compression springs are manufactured
with large spring indexes.
HH, 26.03.2002