You’re likely reading this because you have a metal part or parts to manufacture and you think that the volumes might lend themselves to a true mass production process. We offer some considerations that might help your review and inform your decision about what type of process and supplier to design for – or how to switch processes to reduce costs for an existing component, with the minimum pain.

OEM metal stamping is an ancient process that is at the heart of the most up to date manufacturing supply chains. At its core it is unchanged from the processes used by Bronze Age and Iron Age metalworkers – and yet the nature of tooling, processing methods and precision has kept pace with the manufacturing demands of an integrated and complex supply chain environment.

The family of processes rely heavily on the ductile nature of many metals used in mass production. It isn’t practical to stamp grey cast Iron components – but extraction of net shape parts from plate or strip steel, brass, Aluminium, stainless steel and more can be highly cost effective.

Types of process

Stamped metal processes are diverse and the parts ubiquitous – they can be used in the widest range of applications in manufacturing simple and complex products.

Stamping can be as simple as punching a washer from strip sheet steel, in a single operation.

It can involve simple press forming in a roller – such as pressing the diamond pattern into tread-plate.

It can involve multiple stages of fine and delicate punching and forming of microprecision components, such as tiny (or large) electrical crimp connector parts.

It can be the brute force punching and forming of automotive chassis components in heavy gauge steel.

It can be two sided, four-slide or multi-slide process, depending on part complexity

It can involve deep drawing stages, where material is plastically stretched to form deep cavities or collars.

It can produce flat, simple 2D and increasingly complex 3D forms, to fit demanding applications and result in low cost, reduced part count assemblies.

Simple parts require simple tooling – a punch the shape of the required hole, a die with the same hole for the punch to engage into, and a machine that operates the tooling by applying the necessary force to punch the hole, while clamping the raw material. Punched parts drop through and are collected for later finishing.

More complex parts may require a 2D or 3D net shape to be applied, either before or after punching of the desired ‘blank’ (the term for partially punched/shaped components – also the name for waste material removed to punch a hole).

The most complex stamped parts may require two-slide, four-slide or multi-slide tooling and multiple stages of forming and punching to produce the final component

Advantages of stamping

It’s common for manufacturers and their suppliers to see significant reductions in component costs by working with a capable OEM metal stamper. Replacement or substitution for much more expensive processes, such as forging, casting and CNC machining, can be achieved by utilising or converting part design and production to stamping.

The steady competitive resolve in most product development and manufacturing sectors is to use the lowest cost process available to produce any component – limited only by the need to maintain specification requirements. The potential for OEM metal stampings is to yield significant advantages in reducing costs and time to market, compared with almost all other manufacturing processes – making it the method of preference for metal components in high volume sectors.

Low cost and wide range of raw materials, efficient material use by nesting parts, low operator hazard processes and extremely fast processing of complex parts make this the right choice.

OEM stamping suppliers that employ leading edge process technologies, such as 3D simulation software and virtual prototyping, can complete the evaluation quickly, whether for a miniature part or a large-gauge component.

Simple tooling for complex parts is fast tp design and usually low cost to manufacture. The most complex (multi-stage, multi-slide) tooling is of course more time consuming – but given the complexity of the parts it is developed to manufacture, it remains leading edge competitive.

How stampings reduce costs

Precision OEM stamping manufacture can complete multiple operations and multiple forming stages to produce parts using progressive die-sets, often replacing much more costly and time consuming processes such as CNC machining, forging or casting that generally require multiple suppliers and secondary operations.

The most significant cost reductions result from customer engineers and their OEM suppliers taking the time to optimise the initial part design and Design for Manufacture (DFM) to achieve the maximum benefit from the process capabilities. The OEMs engineers will review the part specifications and evaluate the expected cost of manufacture, the cost of raw materials, and opportunities to simplify assembly (by integrating features and reducing part count and joining processes) to determine whether optimised use of stamping can further reduce costs. OEM metal stamping engineers may be able to offer slight modifications to the part’s design that can produce savings without affecting critical dimensions and function – for example by adding strength to compensate for changed material properties, or by reducing weight.

Many OEM suppliers can offer case studies from their own (and published) experience, showing cost reductions for complex parts that had been previously produced by casting, forging, CNC machining etc. A large part of the potential savings results from finishing operations, which are very often not needed when a part is converted to an metal OEM stamping. Intricate and thoughtfully executed stamping processes commonly reduce piece-part prices by more than half, while cutting production time and logistics dramatically.

Many examples show the use of OEM metal stamping saving 30 percent of the cost of raw materials and production. Well used, the stamping process can drive design to reduce complex sub assemblies and integrate multiple parts into a single component. More complex OEM metal stampings that eliminate the need for more complex materials, instead using low cost flat strip raw material, can reduce secondary operations, and increase the effective strength of the part by reducing jointing and improving the translation of forces and the dissipation of stresses.

Cost of materials is most critical where precious metals are used for plating, commonly the case for electrical connector parts. A capable OEM metal stamper will look for ways to revise the design to minimise the use of high cost raw materials and eliminate waste by nesting parts, where possible.

Design and tooling considerations to optimise

OEM stamping engineers will evaluate various factors in advising revisions to the design of  stamped part, to ensure the component outcome performs as required and to achieve most efficient production and material usage:

Advising about the production process at the OEM and reviewing how the component will be handled in final assembly.

Opportunities for the part to be optimised to eliminate steps in the sub-assembly and final assembly process stages.

Orientating of the part on the raw material strip – and tooling multiple stamped parts into a single tool to allow close nesting of parts by alternating orientation.

Direction of the grain of the metal part – making best use of high strength anisotropy in the raw material – commonly rolled material with a  pronounced longitudinal crystalline grain structure, allowing some of the benefits of forging to be exploited in stamped parts.

Feature addition, for increased stiffness, strength or attachment points.

The exact surface area that must be plated and whether spot plating can be used, to reduce precious metal usage – most significant in electrical connector parts which are stamped and formed in staggering numbers. The Gold use in a typical connector is generally the largest part of the cost of any pin or receptacle part.

The reduction in use of secondary operations after plating.

OEM stamping services

Research and development – support for initial design and design conversion to suit stamping.

Rapid prototyping and trial tool production to validate parts before mass production.

3D simulations of deep drawing, forming, integrated riveting, punching and more.

In-house tool design and build, with a track record in maintaining precision by great design and effective and timely tool maintenance.

Dedicated program management for new products, with particular focus on optimisation of the interface between the OEM and the customer.

In-die sensor technology and advanced quality control systems, to perform QA and tooling condition-monitoring in-process (in addition to) as standalone services.

A measurable track record in reducing costs wherever possible, without compromising quality. Savings often can be identified right at the enquiry stage, when the OEM engineers consult closely with the customer’s engineers on part design and offer suggestions and modifications that can cut costs and production time.

Conclusion

When you need a new metal part or sub-assembly, OEM metal stamping should be considered from the start. The advantages accrue from surprisingly small volumes – particularly when low tooling costs and widely available OEM services are taken into account, making for a very price competitive process, compared with almost all high and medium volume net shape and extractive manufacturing methods.