If you have an injection molding project, there’s a good chance that you are looking at a few different molders/mold builders. It can be challenging to compare quotes accurately to assess your best option. In simple terms, on any given quote you may see various mold specifications, lead times, and a costs. You may have specified to quote an “8 cavity, class 101 mold,” but maybe you see a 20% difference in price from one quote to another and don’t understand why. In this article, we’ll go over some of the “behind the scenes” factors for quoting injection molds.
There are hundreds of small to medium size mold shops throughout the United States, and no two are identical. The type of equipment, machine capacity, and level of expertise determine the kind of work they can complete and how efficiently they can do it.
If a mold builder lacks the capabilities to complete your project, they may need to outsource certain components, which could result in additional cost and timing factors. Lacking the capabilities to do work efficiently can also be an issue. If a mold builder lacks the machinery or technology to get work done quickly, they will need to charge more hours to complete the project.
There are only a certain amount of machine hours and employee hours available to a given shop to complete their work and stay on track with due dates. Mold builders are constantly juggling available machine time against their commitments to customers. The bottom line is, if they are busy, you could be getting a price that represents that. That cost may represent additional employees, over time, the expedited delivery of materials, and possibly outsourcing.
Mold builders often have to make assumptions about a project if they don’t have all the details. These assumptions include cavitation, materials, and timing. We recommend working with a mold builder on all the details of the project and giving them as much information as possible. (For more details, check out this guide to developing a spec for your injection molding project).
It’s important, especially for long term molding projects, that the materials and design standards match the life expectancy of the mold. Specifying a mold class for the project is a great starting point. Mold class specifies the life expectancy of a mold as well as the materials and design standards required. The challenge with mold class specifications is the diversity of design. Each mold is different and can likely be designed in a few different ways, while still meeting the mold class spec. If there is a large difference in price between two mold shops, make sure that they are all quoting to the same specification and have the same design details specified.
First Run (Sampling)
Once a mold is complete, it should undergo a test run, resulting in molded parts that match your print. However, not all mold builders include sampling and post-molding adjustments in their quote. If these operations are not included in the quote, it’s important to understand the total cost of test running, final dimensional adjustments, and the related set-up and shipping charges. Providing all these services under one roof is where the turn-key design, mold building, and injection molder has the advantage.
Although it can be tempting to focus on short term expenses, it is vital to consider the total long-term cost of your project. For example, buying a mold from a low-cost country could save in upfront costs, but you need to know the details of what you are getting. If the mold doesn’t work well, it is unlikely to be worth shipping it back. In that case, you’ll be looking for a local shop to fix the mold and do repairs. For these reasons and many others, it’s often best to look at shops that have design, mold building, mold repairs, and injection molding under one roof.