Impact Extrusion: Systematic Metal Forming

Impact extrusion is more than just a manufacturing method. It enables the cost-efficient and highly reliable production of complex metal parts. Walter Schneider combines precise forming technology with high material expertise. Whether rotationally symmetric or multi-stage: We show you how your component can be realized without waste and with maximum repeat accuracy.

Impact Extrusion: Precision through Forming, Not Removal

Impact extrusion is a bulk forming process in which metallic materials are pressed into a closed tool under high pressure. Unlike machining processes, no material is removed, but rather formed. This means: no waste, no material loss. The material flows into the mold while maintaining its original grain structure. As a result, high-strength, dense, and durable components with excellent surface properties are created. The method is particularly suitable for rotationally symmetric or complex geometries in medium to large series.

Cold and Hot Impact Extrusion Compared

Criteria	Cold Impact Extrusion	Hot Impact Extrusion
Energy efficiency	very low energy consumption no process heat required	additional energy expenditure due to heating higher operating costs
Dimensional accuracy	highest precision tight tolerances within hundredths of a millimeter	good dimensional accuracy slight deviations possible with complex shapes
Strength	maximum strength through material densification preservation of fiber structure	good strength less strain hardening due to heating
Form diversity	suitable for simple or rotationally symmetric geometries	suitable for complex, heavily formed parts
Series production	ideal for large quantities high repeat accuracy	suitable for smaller series with complex geometry
Material flexibility	ideal for well-formable metals (e.g., steel, copper) limited with hard materials	suitable for hard-to-form materials (e.g., nickel alloys)

Understanding Extrusion Processes: Forming Directions and Form Diversity

The choice of impact extrusion direction influences the component geometry and achievable material properties. At Walter Schneider, we utilize all three basic directions – depending on requirements, also in combination.

Forward Extrusion

The punch and the material move in the same direction. This method is particularly suitable for cylindrical solid parts such as bolts or axles. Depending on the material, cross-section reductions of up to 85% are possible.

Backward Extrusion

The material flows against the movement of the punch. This allows for deep hollow shapes with thin wall thicknesses to be created – such as sleeves, caps, or cups with closed bottoms.

Combinations & Special Forms

For complex parts, we combine multiple forming directions in one tool. A typical example is extrusion with bilateral calibration, resulting in high-precision hollow bodies with defined internal geometries – rotationally symmetric or asymmetric.

Lateral Extrusion

The material flow occurs crosswise to the movement of the punch. This allows form elements such as cross ribs, cross holes, or lateral features to be directly formed – without additional processing.

Impact Extrusion: The Process in Detail

1. The forming process
The blank – typically a wire segment or a pre-cut slug – is inserted into a precisely designed tool. A punch presses the metal into the die under high pressure. The material flows into all cavities of the form without material separation. An exact component with a compact microstructure and high repeat accuracy emerges.

2. The tools
We develop and manufacture all forming tools ourselves – from high-strength tool steel. Our tools are engineered for high durability and enable extremely tight tolerances. The development is carried out digitally, with direct feedback to the component design.

3. Calibration and post-processing
For particularly demanding parts, we calibrate the internal contour in a second step. Trimming, punching, thread pressing, or vibratory finishing can also be integrated. Our goal: a net-shape production, where the component is immediately ready for use – without additional processing steps.

Application Examples from Impact Extrusion

Whether solid bodies, hollow forms, or complex geometries – extrusion offers a wide range of possibilities. The following component types have proven particularly successful in practice.

Rotationally Symmetric Solid Parts

These parts are characterized by continuous cross-sections and high mechanical load capacity. Impact extrusion replaces turning here – with greater strength and less material consumption.

Bolts with integrated head shape – e.g., for connections under shear or tensile stress
Axles with collars or chamfers – for precise guidance or rotating applications, for example
Pins with defined diameter progression – e.g., for bearings or plug connections.

Hollow Bodies with High Dimensional Accuracy

Hollow shapes particularly benefit from impact extrusion because they can be manufactured in one piece – without welding or deep drawing.

Sleeves with internal calibration – e.g., for housings, bushings, or insulators
Cups with bottom – for closed hollow parts with high axial-symmetrical load
Hollow shafts – rotationally symmetrical and thin-walled, ideal for drive components.

Functional Geometries through Forming – With Added Value

Impact extrusion can do more than just ’round’. Through targeted forming, functional features are directly formed that would normally have to be milled or drilled afterward.

Lateral projections and transverse ribs – directly formed, no machining effort
Transverse bores or longitudinal grooves – achievable through lateral extrusion
Multistage shape elements – e.g., with varying wall thicknesses, diameters, or transitions.

Materials We Extrude – Our Material Expertise

The choice of the right material determines the formability, strength, and lifespan of the component. At Walter Schneider, we process not only standard metals but are also specialized in hard-to-form alloys.

Stainless steels (e.g., 1.4016, 1.4301, 1.4567):
For applications with corrosion, temperature, or hygiene requirements. Typical in medical technology, food industry, or plant engineering.
Copper and lead-free copper alloys: Highly conductive, antibacterial, easily formable – ideal for electrical connectors, sanitary technology, and medical components. Lead-free variants for ROHS-compliant products.
Aluminum and aluminum alloys: (e.g., EN AW-6060, -6082)
Light, easily formable, for weight-optimized components with medium strength. Particularly in demand in sports equipment manufacturing, connection technology, or lightweight construction applications.
Special alloys and high-performance materials: Including heat-resistant nickel alloys or chemically resistant special steels. Used in aviation, energy technology, or special plant engineering.
Tempered steels, free-cutting steels, and carbon steels: For components with high mechanical stress, where dimensional accuracy, wear resistance, and long-term durability are crucial.

All materials are checked by us for their extrudability. If necessary, we adapt geometry and tooling specifically to the material properties – for optimal forming results and stable series processes.

Benefits of Impact Extrusion at Walter Schneider

Full Material Utilization

During pressing, almost no waste is produced. This is particularly economical with expensive materials such as stainless steel, nickel, or copper.

Significantly Higher Strength

Since the grain orientation of the material is maintained, no predetermined breaking points arise. This increases the endurance under load and prevents early failure in use.

Dimensional Accuracy in Series

Our tolerances are within the hundredths of a mm range – even with several million pieces.

Reduced Post-processing Effort

Due to net-shape manufacturing, many classic machining steps are unnecessary. Turning, milling, or grinding are not required depending on the final geometry – saving time, tools, and costs.

Sustainable Manufacturing

The forming is carried out cold. No process heat is needed. The energy input is low, waste is minimal. Additionally, we reduce transport through process integration.

Short Cycle Times, Low Piece Costs

Thanks to multistage tool concepts, our processes are highly automated. This allows for piece costs to remain low – ideal depending on material and geometry starting from 50,000 to 100,000 components annually.

Contact

Do you have a component drawn, a sample at hand, or a first idea in mind? We check for you whether and how the component can be economically extruded. Even for demanding requirements or unknown materials. Get in touch with us now – fast, direct, and without obligation.