Steel stampings 0.2 - 3 mm

During production by Karl Naumann GmbH, standard tolerances in accordance with ISO 2768-m are aimed for in progressive stamping for car body components, whereby functional dimensions can be mechanically narrowed to ±0.02 mm. The elastic springback of high-strength grades acts as a physical limit, which leads to unstable melt pools if not observed. In contrast to conventional processes, we secure these narrow limits using integrated sensors to guarantee dimensional accuracy for subsequent laser welding processes.

An increasing carbon content in the material increases the hardness and shear strength, which mechanically leads to a higher cutting resistance and an increased proportion of breakage at the cutting edge. This reduced ductility favors burr formation and makes it more difficult to form smooth functional surfaces on steel stampings with complex contours. Karl Naumann GmbH therefore recommends soft-annealed grades such as DC01 in accordance with DIN EN 10130 for delicate geometries in order to prevent tool breakage due to overloading.

The local shear stress creates an edge zone with massive work hardening and induced residual stresses, which mechanically increases the hardness but drastically reduces the residual elongation at break. In dynamically loaded chassis components, this zone acts as a starting point for edge cracks, which critically reduces the service life. We monitor this area in precision stamped steel parts to ensure that embrittlement does not lead to sudden brittle fracture under vibration load.

When designing steel stamped parts for welded assemblies, the edge must be designed in such a way that it is free of organic residues in order to prevent chemically induced pores in the seam. Mechanically, a zero gap is required, which is why we manufacture components with minimal edge indentation, as too large a gap would allow the laser beam to fall through. We validate these requirements using a validated process chain to ensure the strength of the joint in vehicle construction.

A no-go defect is uncontrolled burr formation above 0.1 mm, which acts mechanically as a notch and accelerates crack initiation during load changes. In high-voltage e-mobility environments, burrs can also detach and cause short circuits by bridging air gaps. We therefore supply stamped steel parts with deburred edges that have been freed from these sharp-edged protrusions by vibratory grinding or edge rounding.

The mechanical deformation during strip stamping leads to a dislocation density in the microstructure, which massively increases the yield strength locally. This effect makes subsequent bending operations on steel stamped and bent parts more difficult, as the material reacts brittle and tends to crack. Karl Naumann GmbH calculates this hardening in advance in order to dimension the radii in such a way that the mechanical integrity of the stamped sheet steel parts is maintained.

A reproducible hole position is ensured by permanently integrated finder pins in the progressive die, which mechanically force-center the strip in each station. We also use 3D optical measurement to immediately detect deviations in the micrometer range and correct the feed rate using software. A deviation outside the tolerance center endangers the automated stud setting, which leads to an immediate production stop.

For quality assurance, we use image-processing optical 3D inspection, which, in contrast to tactile measurement, works without distortion and verifies contour accuracy every second. In addition, we carry out a 2D optical measurement of the positional and dimensional tolerance in order to generate statistical evaluations for process capability (Cp/Cpk). Without this validated data, approval for safety-critical steel stamping components is not technically justifiable.

The steel stamped parts with initial sample test report documents the complete conformity of the tools with the design drawing under series production conditions. It mechanically proves that all functional dimensions and the chemical composition of the steel (e.g. S355MC) comply with the specifications. Without this proof, there is a risk of serial defects, which massively jeopardizes product liability during component assembly.

For stamped steel parts with tight tolerances in switch cabinet construction, we manufacture components with deviations of ±0.1 mm to ensure the mechanical accuracy of fit of the rail systems. Physically, distortion beyond this limit leads to distortions that jeopardize the degree of protection (IP class) due to leaking joints. In contrast to standard sheet metal, we use precision punching to ensure dimensional accuracy for automated enclosure integration.

When punching galvanized steel in accordance with DIN EN 10130, the mechanical shearing leads to structural changes that can locally increase the specific electrical resistance in the cutting zone. This is critical for steel stampings for contact and earth connections, as hotspots can occur under high current loads. Karl Naumann GmbH optimizes the cutting gap geometry in order to keep the disturbed edge zone to a minimum and to maintain the thermal stability of the connection.

We prefer to use micro-alloyed grades or cold-rolled sheet such as DC01, as these offer high mechanical repeatability in complex forming operations. These materials allow tight bending radii in steel stamping and bending parts without the risk of edge cracks that would occur with more brittle structural steels. An exclusion criterion for precision applications is an uneven microstructure, as this has a negative impact on the flatness of the stamped steel parts.

Steel stampings with defined edge quality are essential to prevent mechanical damage to the conductor insulation caused by sharp burrs. An uncontrolled burr leads to the destruction of the insulating layer under vibration, which results in chemical-electrical leakage currents and short circuits. We guarantee complete edge rounding through vibratory grinding to ensure operational safety in switch cabinet construction.

Excessive roughness of the base material hinders the homogeneous formation of a zinc coating during galvanizing, which chemically reduces the protective effect. Mechanically, this leads to premature rusting of the coating on sharp-edged punched steel parts with a hole pattern. Karl Naumann GmbH monitors the defined surface roughness in order to guarantee the required corrosion resistance for outdoor use in electrical engineering.

Progressive die stamping is technically superior when large series of steel stampings with integrated threaded inserts or complex pull-throughs for screw connections are to be produced. Mechanically, the system ensures the exact positional relationship of all features to each other, while manual repositioning of insertion tools adds positional tolerances asymmetrically. This is essential for the error-free assembly of automated switching systems.

We use 3D optical measurement to simultaneously verify all distances and diameters for steel punched parts with multiple openings. Mechanically, this ensures that the accuracy of fit for multi-contact strips is maintained over the entire component length. In contrast to manual spot checks, this system also detects creeping tool wear before the dimensional accuracy leaves the tolerance limit.

In the event of damage (e.g. fire due to material defects), documented traceability enables the affected batch to be identified right back to the melting of the steel. Chemical impurities in the material can reduce the mechanical strength of highly stressed assemblies. Karl Naumann GmbH guarantees this transparency in order to minimize liability risks for plant manufacturers in automation technology.

The design is based on the definition of the controlled edge zone in order to mechanically minimize notch effects on the holes. Physically, a rough hole wall under alternating mechanical load leads to fatigue failure of the joining technology. We use precision punching to achieve smooth cut surfaces that significantly increase the service life of the steel punched parts for assemblies.

For highly stressed assemblies, we manufacture stamped steel parts with tight tolerances of ±0.05 mm to ensure exact force transmission in threaded connections. Mechanically, a deviation beyond this dimension leads to eccentric loads on the screws, which can lead to premature shear fracture. Karl Naumann GmbH uses precision stamping to guarantee the accuracy of fit for connection technology in steel construction.

Work hardening during the belt punching process increases the local hardness and tensile strength, which mechanically increases the stability of angles and tabs. Physically, however, the toughness decreases, which makes the material more brittle and can break without warning if overloaded. We monitor this effect in steel stamped and bent parts to ensure that the hardening does not exceed the permissible limits for railroad technology.

To improve protection, we use galvanizing or phosphating to chemically passivate the surface against oxidation. Mechanically, a zinc coating also offers a certain degree of protection against abrasive wear during assembly. Karl Naumann GmbH recommends additional coatings for steel stampings with surface treatment in bridge or building construction in order to increase the service life to over 30 years.

Steel stampings with a defined edge quality are essential to ensure a clean material flow during riveting and clinching without edge cracks. Mechanically, a burr acts as a foreign body that distributes the closing force of the tool asymmetrically and thus reduces the strength of the joint. By rounding the edges, we guarantee that the steel stampings for component assembly are optimally prepared for these cold joining processes.

A critical defect is an undefined burr on the underside of hole-punched parts, which mechanically prevents the screw head from making full contact. Under load, this burr sets plastically, which reduces the preload force of the connection chemically and physically and the screw can loosen due to vibration. We therefore supply stamped steel parts with deburred edges to ensure safety in conveyor technology.

This is necessary if the components have to undergo several bending operations and hole pattern embossing sequences in one stroke in order to maintain high dimensional accuracy. Mechanically, the continuous strip guide ensures that the angular relationships are precisely maintained, which is crucial for the housing integration of rail systems. In contrast to insert stamping, this minimizes rejects for steel stamped parts in large series.

The evaluation is carried out by statistically evaluating the critical dimensions using SPC, taking into account the high material strength of materials such as S355MC. Mechanically, tool wear leads to dimensional deviations more quickly here, which is why the process capability must be monitored at close intervals. A stable process is the prerequisite for the long-term resilience of components in agricultural machinery.

We use optical 3D inspection to verify the pitch accuracy over the entire length of stamped steel parts with multiple openings. Mechanically, this ensures that bolt fields can be joined without distortion. Karl Naumann GmbH documents these values in a 3D measurement report to verify compliance with the dimensional accuracy for the joining technology.

Documented traceability is mandatory for approval under building law in order to be able to prove the material batch and its mechanical characteristics (e.g. yield strength according to DIN EN 10025) in the event of failure. Without this documentation, the safety of the highly stressed assemblies cannot be certified. We ensure that all steel stamping components can be clearly assigned to their lot of origin.

Optimization is achieved by minimizing the thermally unaffected but mechanically disturbed edge zone in order to avoid structural inhomogeneities during subsequent welding. Physically, an excessively work-hardened edge leads to local stress peaks during welding, which can provoke cracks. We use precision stamping to create a clean starting point for steel stampings for welded assemblies in mechanical engineering.

Even microscopic metal particles or oil residues on the stamped steel parts can cause the lubricants to resinify chemically and physically and block the mechanism. Mechanically, such residues lead to irregular oscillations of the balance wheel. We guarantee extreme component cleanliness through ultrasonic cleaning to ensure the reliability of steel stamped parts for assemblies in the watch industry.

We prefer to use high-alloy, stainless steels in accordance with DIN EN 10088, as these combine high mechanical hardness with chemical resistance to oxidation. Work hardening during the strip stamping process is used specifically to produce wear-resistant functional surfaces without additional hardening. One exclusion criterion is the use of brittle structural steels, as these would lead to tool breakage in the filigree punched parts.

Precision punching is superior if the components have a functional thickness of more than 0.5 mm and require right-angled edges for force transmission. Mechanically, punching offers greater repeat accuracy when forming functional ramps and openings. In contrast to etching, progressive stamping also enables the integration of bending operations for steel stamped-bent parts in the same work step.

The controlled edge zone ensures that there are no microcracks that could lead to sudden breakage under the permanent mechanical tension of the tension spring. Physically, any structural disturbance acts as a crack initiator. Our company validates this area by metallographic grinding in order to guarantee the fatigue-resistant quality of components for high-quality chronometers.

For quality assurance, we use high-resolution optical 3D inspection to verify the hole pattern and contour accuracy in the sub-micrometer range. Mechanically, this ensures the exact centering of the shafts. The results are archived in a test report in order to provide complete proof of compliance with the strict standards for measuring and testing technology in watch production.

Excessive roughness on the tooth flanks leads mechanically to abrasive wear, which generates microscopic abrasion and gradually destroys the mechanics. Physically, a rough surface increases the frictional heat, which causes the lubricant to age chemically. We use grinding or brushing to ensure a defined surface roughness that is optimized for precision mechanics.

Laser marking allows the smallest steel stamped components to be marked with serial numbers without introducing mechanical stresses into the component. Physically, the microstructure remains unaffected, while the legibility for documented traceability is permanently maintained. This is essential for quality assurance and counterfeit protection for high-quality watches.

The evaluation is carried out by statistically monitoring the stroke constancy and the punching force using SPC in order to support a zero-defect strategy. Mechanically, any instability in the process leads to unacceptable fluctuations in accuracy. A process is only considered capable if the high dimensional accuracy remains stable over the entire small series without manual intervention.

The steel stamped parts with initial sample test report is the binding document that mechanically confirms the technical feasibility of the design. It proves that the stamped steel parts achieve the required precision according to the drawing under real production conditions. For the purchasing department, this is the only guarantee against subsequent assembly problems in the highly complex assembly of a mechanical movement.