Designing parts for manufacturing can be an interesting challenge. We all want to create unique and innovative components that look good and function well. More importantly, we want them to be affordable for our customers and profitable for our business. Having a better understanding of what goes into the cost of a machined part can help us improve our designs and save money in the process.

What Impacts the Cost of Machined Parts

There are a number of contributing factors when it comes to determining part prices. Some are unavoidable given the requirements of a part (size, material, machined features) but others can be changed or minimized to same time and money in the manufacturing process.

Size

This one is a no-brainer. Bigger parts cost more. They require more material. They demand more robust work-holding which adds to setup time at the machine. Operators may need to use more expensive tooling as machined components increase in scale.

Material

Material selection is very important when designing a part. While it should be plain to most that certain materials are more costly than others, it’s important to remember that certain materials also machine differently as well. You could potentially save a few bucks going with one type of metal over another, but you may end up spending far more because of its difficulty to machine. Innovations in plastics and metals have opened up a wide range of possibilities in manufacturing, so it is important to consult your production shop and material vendor to find the best solution for your needs.

Sticking to standard hole sizes and material types/thicknesses can be a big time/money saver

Machine Type/Operation

A customer could be in the market for a simple 2D template. There are any number of ways to cut something like this out (laser, waterjet, plasma, EDM, etc) but they each come with their own price tag. Knowing the difference between machines and their associated operating costs can save or cost you money when it comes time to manufacture.

Part Design/Dimensioning

Parts design often has a direct impact on machining time, which in turn affects the part price. The more features that need to be machined, the longer it takes so when looking to cut costs, it’s important to consider the necessity of machined elements and whether certain aesthetic features could be removed to decrease machining operations.

Dimensioning is also a key contributor to part cost. In most cases, tighter tolerances will lead to increase part prices because it takes programmers/operators additional time to machine, inspect and trouble shoot discrepancies to ensure accuracy and precision in a part.

Tips For Reducing Machined Part Costs

Knowing what goes into a part price can help us be more deliberate about our design choices, so that we can be confident we will feel good about the cost and quality of our finished product. Here are a few more considerations to help save money on your machined parts.

Tolerances/Finishes

Don’t ask for a tighter tolerance than is required for your part to function as intended. Time equals money, and tighter tolerances take longer to machine (they also take longer to inspect.) This applies to surface finish call-outs as well. It can take significantly longer to achieve a desired finish due to additional/slower machining passes, and the inspection process requires added time and equipment which ups the finished part price.

Part Design

Every hole, pocket, surface, chamfer takes time to machine. An easy way to decrease manufacturing costs is to remove unnecessary or overly complicated part features, especially those that are solely aesthetic and do not enhance a part function. Deep holes/pockets, contoured surfaces and non-standard geometry are main culprits for increased costs as they require more time/tooling to machine properly. Another cost saving measure would be to break up a part into multiple components (think weld instead of bend/machine, or add bolt holes for assembly.) This can decrease part complexity, limit setups and machining operations, and ultimately save a lot of time and money.

Standardize Whenever Possible

Sticking to standard hole sizes and material types/thicknesses can be a big time/money saver. Tooling and material will be less costly, and more readily available which helps decrease lead times as well as part prices.

Quantity

This is a big one. Part price decreases as quantities increase. Most shops will have a minimum setup/programming fee to machine a part, and that cost will not change whether the order is for 5pc or 5,000. Though machining time won’t change on a per part basis, these blanket costs associated with material, programming, setup, etc. can all be amortized over a larger number as the production quantities increase.