Metal injection molding is an alternative process to machining parts out of raw metal stock. Many original equipment manufacturers (OEMs) of firearms and defense products are mandating that their part suppliers outsource to secure price advantages while maintaining strict quality requirements.
With price pressures and quality requirements getting more stringent by the day, MIM often is the answer. Starting with the premise that an existing or new part project requires a process evaluation, the following considerations enter the picture.
Foremost is an answer to this question: “Is your part project a viable MIM candidate?”
According to Smith Metal Products, a provider of MIM solutions, metal injection molding can be an effective option for achieving precision parts without machining since they can be produced faster and usually with no secondary operations. However, not all parts qualify for this alternative solution.
Smith Metal Products recommends using the following criteria to evaluate whether a given part is a good candidate for MIM:
- Annual volumes of 10,000 pieces or more; the more, the better
- Under 100 grams (3.5 ounces) finished part weight
- All dimensions of the component are 3” or less
- Maximum wall thickness of 3mm (.125”) or less, or cored out to this thickness
- Must be ferrous metals (no aluminum, copper, brass, zinc or magnesium)
- Medium to high complexity
Using these criteria, Smith Metal Products compared the cost of producing 100,000 pieces of a part made with CNC machining with that of MIM. Here's what the company came up with:
For more information, visit the Smith Metal Products website.