Stamped Parts for the Insert/Overmolding Market

What Is Insert Molding and How Are Stamped Parts Used in the Process?

Insert molding is a subcategory of injection molding. It’s a common technique for creating strong yet cost-effective parts, combining metal inserts and plastic molded components to generate reliable, durable products.

What Is Insert Molding?

Insert molding is an industrial manufacturing method that relies on current technologies in injection molding. It follows the same principles as conventional plastic injection molding, except that insert molding requires the addition of an insert.

Typically metal in material construction, the insert goes into the mold prior to the introduction of molten plastic so that the metal will become a permanent part of the plastic upon cooling. This forms a single insert molded part that combines the benefits of engineering plastic, which allows for lightweight parts with improved strength and versatility to accept various fasteners with compression limiting features.

How Are Stamped Parts Used in the Process?

The metal insert molding process begins by placing one or more stamped metal inserts into a mold. Once an insert is in place, the injection molding press will inject heated plastic in molten form into a mold in the shape of the desired part, encapsulating the metal insert. The majority of thermoplastic resins are applicable for insert molding, and aluminum, stainless steel, and copper alloys like brass are common insert materials. The process is often meant to encapsulate threaded inserts/compression limiters and reinforcement brackets.

The plastic will harden as it cools, curing to take the mold’s shape. The next step is to open the mold. Depending on the type of press, the finished part will either eject from the mold or an operator can remove it manually.

How Does ESI Support Insert Molding Projects With Precision Stamped Metal Parts?

ESI has provided quality metal stampings to diverse industries for over 30 years. We utilize progressive and fourslide metal stamping techniques, cold heading, and machining to make custom, highly engineered inserts for your insert molded parts. Our expert team of designers and engineers can support you in finding the right metal material and insert for your application.

Unlike some metal stamping companies, we make our own tooling in-house, which allows us to think outside the box and help you design and produce optimized products. Our press capacity ranges from 5 to 150 tons and our automated equipment can achieve parts with tolerances of 0.001 inches. We’re capable of handling both low and high production volumes, with our team fulfilling orders of anything from 1,000 parts or less to more than 20 million to suit our customers’ varied needs, all with on-time delivery. We also ensure that we check every part for optimal quality during production as we use built-in vision inspections in our machinery.

Common stamped parts for insert molded products include the following:

• Busbars
• Compression limiters
• Contacts
• Mounting plates
• Reinforcement brackets
• Rolled and crush bushings
• Standard, transmission, and selective-plated lead frames
• Terminals
• Threaded inserts

Whatever your needs, ESI offers the support and superior customer service you expect from a small job shop but with the sophistication of an international manufacturer.

Insert molding is an ideal solution for widespread applications because it offers a wealth of advantages.

Enhanced Part Dependability and Performance

As discussed, insert molded parts are lightweight yet strong given the combination of plastic and metal, allowing for a highly functional part. The thermoplastic resin secures each part in place, increasing the ability of the part to withstand shock and vibration. Using insert molding also minimizes the chance of component misalignment, loose parts, or incorrect terminations for heightened reliability.

Versatility of Design

Insert molding delivers excellent design flexibility, giving designers and engineers endless options for part shapes and intricate details. They can arrange the inserts in numerous ways, and engineering plastics are highly versatile, allowing for simple or complex parts. The process creates a bond between the plastic and metal that minimizes the need for things like fasteners and adhesives in the design.

Lighter Weight and Compact Size

Without fasteners or connectors, this allows part designers to develop more compact, lightweight components with fewer parts. That said, using the resin in combination with metal inserts still allows insert molded parts to be quite strong so that you don’t sacrifice durability for weight.

Decreased Costs

The process incorporates several different parts with thermoplastic, helping you save on both labor and component assembly while reducing weight.

At ESI, we work with a wide array of ferrous and non-ferrous metal types and grades to create strong inserts for insert molded components. Examples of our material options include:

• Aluminum
• Copper
• Beryllium copper
• Phosphor bronze
• Brass
• Steel
• Stainless steel
• Carbon steel
• Titanium

Our machinery can work with materials ranging from 0.005 to 0.125 inches thick.

From our state-of-the-art facility in North Branford, Connecticut, the ESI team manufactures and assembles highly engineered products with a strong focus on quality assurance, cost-effectiveness, and timely delivery. We take on projects of all sizes, and we’re equipped to meet your project challenges for virtually any insert molding application.

Contact us to learn more about stamped parts for the insert molding market and discover how ESI can help you achieve exceptional quality at competitive prices. You can also request a quote for specific information pertaining to your next project.