Prototype tooling, also known as soft tooling or rapid tooling, is a method to create the tooling for, primarily, plastic injection molding without the great expense or lead time required for the final hard steel tooling for the final mass production run.
As the name suggests, the parts created from this tooling will often be near-production prototype parts using the same materials as planned for final products that are manufactured at low cost (thanks to cheaper tooling) to allow the manufacturer to validate and test them during the early stages of the new product development process.
Because we’re mimicking the final injection molding process and materials used in production, we have a very good idea of how ready the parts are for mass production. Also, during the prototyping process, it may be necessary to tweak the product or part design a number of times and create quite a few prototype pieces, and the more durable soft tooling will stand up to this extended use very well.
What can be used to create rapid tooling?
A rapidly made mold can be made from:
- Silicone rubber (least durable)
- Aluminum alloy
- Steel/aluminum hybrid
- Soft steel (most durable)
At most these molds will be made in a couple of weeks or so, which compares favorably with the 60 days it will averagely take to create mass production hard tooling.
Are there alternatives to soft tooling?
Yes, it’s possible to create prototype parts using 3D printing (additive manufacturing) and CNC machining. These are legitimate rapid prototyping methods, but they have drawbacks in comparison to soft tooling, especially the cost-effectiveness of using them for larger numbers of pieces.
Benefits of rapid tooling for prototypes
Here’s a summary of some of the key benefits of prototype tooling:
- The word rapid has been mentioned and creating molds created via prototype tooling is very fast, often taking just hours or days to make rather than several weeks.
- Due to the smaller investment in this kind of tooling, it’s possible to make relatively small runs of prototype parts to check the part design, tolerances, finish, production processes, and more, before going into mass production where mistakes would be a costly disaster.
- Rapid tooling generally creates an injection mold from a less durable material than hardened steel used in mass production tooling. Because it’s still a molds, as opposed to creating parts through other alternative methods, it means that very accurate parts can be made from production materials and mimic real product strength, etc.
- Parts made from 3D printing or CNC machining may not be able to reproduce the production finish you need, have the right strength, or be within a very tight tolerance of your measurements.
- Soft tooling for prototypes is more suited to larger pre-production runs due to lower per-piece costs over time than 3D printing and CNC machining whose per-piece costs remain fairly static regardless of how many are made.
Learn more about rapid prototype tooling and more
Here are some resources that go into more detail about the processes mentioned here:
Also separate resources for the alternatives, too:
