What is Bridge Tooling?
Bridge tooling is the process of creating temporary moulds or tools to produce small volumes of parts before the final production tooling is ready. It is a cost-effective and efficient method of bridging the gap between product development and full-scale production, hence why it is called ‘bridge tooling.’
It is the stage in the product development process between prototyping and production.
Bridge tooling is employed in circumstances when the final mass production tooling is still being designed or manufactured, but there is a need to produce a small batch of parts for testing, market validation, or short-term production requirements.
Less expensive materials are often utilised, such as aluminium or epoxy.
This temporary tooling mimics the intended part design and dimensions closely. Once final production tooling is ready, it replaces the bridge tooling, and mass production can begin.
How are Bridge Tools Manufactured?
To manufacture bridge tools in the toolmaking process, the following steps are typically followed:
- Design and Planning: The toolmakers work closely with engineers and designers to create a detailed design of the bridge tool. This includes understanding the specific requirements, dimensions, and functionality of the tool.
- Material Selection: Choosing the appropriate material for the bridge tool is important to ensure durability and performance. Typical materials include aluminium and various alloys, depending on the specification required, such as strength, corrosion resistance, and cost.
- Machining: The selected material is cut and shaped using various machining techniques like milling, turning, drilling, and grinding. Computer Numerical Control (CNC) machines are often used for precision and accuracy in these operations.
- Heat Treatment: Depending on the material and requirements, heat treatment processes like annealing, hardening, tempering, or case hardening may be applied to improve the mechanical properties of the tool, such as hardness, toughness, and wear resistance.
- Surface Finishing: Once the desired shape is achieved, the bridge tool is subjected to surface finishing processes such as polishing, buffing, or grinding. This helps to remove any surface imperfections, improve aesthetics, and enhance functionality.
- Assembly: If the bridge tool consists of multiple components, they are assembled together using techniques like welding, brazing, or fastening, to ensure all parts fit precisely.
- Inspection and Quality Control: The manufactured bridge tool undergoes thorough inspection and quality control processes to check for dimensional accuracy, functionality, and durability. This may involve the use of measurement tools such as coordinate measuring machines (CMM) or optical measurement equipment.
- Modifications and Adjustments: Bridge tools are tested to ensure that they meet the specified requirements. If tooling modifications are required, they are made at this stage.
It is important to note that the specific manufacturing process can vary depending on several factors, such as the complexity of the bridge tool and the quantity of parts required.
What are the Main Benefits of Bridge Tooling?
The main benefits of bridge tooling include:
- Cost-effectiveness: Bridge tooling is less expensive compared to permanent tooling. It allows for limited quantities of parts at a lower cost.
- Quick turnaround: Bridge tooling enables rapid production by reducing the design and manufacturing time required for permanent tooling.
- Iterative design: Design improvements can be made easily during the development phase, prior to investment in permanent tooling.
- Validation of design: Bridge tooling provides an opportunity to evaluate functional prototypes to ensure the design meets the performance criteria before mass production.
- Low volume production: Bridge tooling is ideal for producing small to medium quantities of parts, bridging the gap between prototyping and mass production.
- Material selection flexibility: Bridge tooling allows for the production of parts in various materials, including plastics, metals, and composites.
- Improved time to market: By enabling faster production and prototype validation, bridge tooling can expedite the product development cycle, thereby reducing time to market.
Why Use Aluminium Instead of Steel for Bridge Tooling?
There are several reasons why aluminium is preferred to steel for bridge tooling:
- Weight: Aluminium is much lighter than steel. This makes it easier to handle and transport during the tooling process. It also reduces the load on the entire structure, making it more efficient and cost-effective.
- Machinability: Aluminium is relatively softer and has better machinability compared to steel. It can be easily shaped, cut, and machined to create complex bridge tooling designs. This saves time and cost during the manufacturing process.
- Durability: Despite being lighter, aluminium has excellent strength-to-weight ratio. It can withstand heavy loads and forces, making it a durable material for bridge tooling. Aluminium also has good resistance to corrosion, ensuring a longer lifespan.
- Thermal Conductivity: Aluminium has high thermal conductivity compared to steel. This property helps in efficient heat transfer during the tooling process, allowing for faster cooling and quicker production times.
- Cost: Aluminium is generally less expensive compared to steel, making it a cost-effective choice for bridge tooling. It requires lower maintenance costs and can be recycled, contributing to sustainability and cost savings in the long run.
- Flexibility: Aluminium is a highly flexible material, allowing for various design possibilities and customisation options. It can be easily formed into different shapes and sizes, providing flexibility in bridge tooling designs without compromising structural integrity.
Overall, the choice between aluminium and steel for bridge tooling depends on the specific requirements of the project, including factors such as load-bearing capacity, design constraints, and environmental conditions.
Bridge Tooling by Industry
Bridge tooling is most typically suited to industries that require rapid prototyping and short production runs. Industries which frequently benefit from bridge tooling include:
- Automotive: Bridge tooling is essential during the development of new vehicle models or when making changes to existing ones. It allows for the production of prototypes, testing parts, and limited production volumes before finalising the tooling design.
- Consumer Electronics: With evolving technology, consumer electronics companies often require quick turnaround times for small production runs. Bridge tooling enables them to produce refined prototypes and test them for functionality and aesthetics.
- Aerospace and Defence: Aerospace and defence rely on rapid prototyping and low-volume production to evaluate designs and ensure high performance and safety standards.
- Medical Devices: Medical device manufacturers often require prototyping and low volume manufacturing due to regulatory approval processes and market demand. Bridge tooling allows for the rapid production of medical devices for testing and early market entry.
- Industrial Equipment: Companies that develop industrial machinery and equipment may utilise bridge tooling to validate their designs before investing in full-scale manufacturing. It helps to ensure that the final product meets performance and durability specifications.
- Product Design and Development: Bridge tooling also finds applications in various product design and development firms as part of the trialling process during new product development.