Our bainitic hardened and tempered PT-strip (pre-tempered) has an ideal combination of pre-adjusted component strength, good formability and good bendability. Thanks to this union of opposites it offers optimal spring properties, even for dynamic, highly-stressed parts. It is used, for example, in connecting, fastening and spring clips in mounting applications.
We also offer a special form of our bainitically hardened and tempered steel strip for cutting, stamping, and creasing lines. Thanks to a special annealing process, this makes it possible to combine a hard, durable material core with a soft, flexible surface.
Waelzholz owns special, high-performance machinery for bainitic hardening and tempering and is specialized in the production of PT-strip. This is how we guarantee absolutely homogeneous processing and forming properties as well as constant mechanical-technological characteristic values. Our customers benefit from the high- reproducibility of their components, as this translates to process stability. The greatest advantage of using PT-strip is the absence of time-consuming and expensive piece hardening. Stamped, bent and formed parts can be manufactured in one single step without any deforming or heat cracks. The result is optimal processing efficiency.
Specifically, the good formability and bendability facilitate a wide range of demanding forming operations such as contours of stamped holes with a collar or dome-shaped drawing, notches and beading.
The differences between longitudinal bending and transverse bending are also minimal thanks to the homogeneous and fine-grained microstructure of the material. Because of this characteristic, our customers profit from maximum reproducibility of their parts and extremely high process reliability.
PT 120 with a thickness of 1.7 mm (0.067") and a tensile strength of Rm = 1150 MPa (167 ksi)
1 Bending radius longitudinal to rolling direction
2 Collaring hole by drawing
3 Bending radius transversal to rolling direction
4 Notch
You will find the possible bending radii according to material thickness in the following table.
Locking springs used in car seats prevent the seat backs from tilting. The challenge is that soft materials that are subsequently piece-hardened do not achieve the necessary tolerances. Pre-hardened strip from Waelzholz, on the other hand, offers excellent formability with a strength of up to 1,500 MPa, eliminating the need for piece hardening.
| DIN EN 10132-4 | Transversal to RD in mm | Longitudinal to RD in mm |
| PT90 | ||
| PT100 | ||
| PT120 | ||
| PT140 |
For more information on the PT-strip products, please refer to data sheets provided.
