We plan and produce traction springs in round wire (ø starting from 0,10 mm). We use raw material according to UNI EN 10270-1, UNI EN 10270-2 and UNI EN 10270-3, but also special raw materials and high performances alloys. We produce springs that comply with UNI EN 13906-1, with several kinds of hooks and with the client’s specifications and drawings, in different lay outs and with the required surface treatments.
Technical Specs
The tension spring is usually made of wire of circular cross section, wound in a helix around an axis, with coils in contact or not, which reacts to an axial force which tends to extend the length of the spring, with or without initial tension. This spring, ideally considered as a rigid body, generally is subject to tensile load acting along its axis.
Before undertaking the design calculations of a spring, we must consider the requirements to be achieved, in particular by defining the preload, which is the force that must be applied to the spring in order to overcome the force that keeps the coils tightened.
The calculation of the cold coiled springs under dynamic loading is difficult, because of the complicated shape of these springs. When the springs are extended, there is a non-uniform distribution of torsional stress due to the curvature of the active coils, as in the case of compression springs. The maximum torsional stress must be calculated using the correction factor of the stress k.
Materials
Types of materials used for the production of traction springs:
UNI EN 10270-1
SM
SH
DM
DH
Phosphate, patented, galvanized, zinc aluminate, with particular strengths
UNI EN 10270-2
FDC
FDCrV
FDSiCr
TDC
TDCrV
TDSiCr
VDC
VDCrV
VDSiCr
UNI EN 10270-3
1.4310 NS
1.4310 HS
1.4401
1.4568
with particular strengths
UNI EN 12166
Copper
beryllium copper
phosphor bronze
UNI EN 10088-3
1.4021
1.4462
1.4539
1.4016
1.4597