Hardware Considerations for CNC Machined Parts

The engineers we work with are, without a doubt, the true experts on their parts. They know how their parts must be designed to function effectively, and we respect that. 

However, as experienced precision machining professionals, we offer a unique perspective through the lens of Design for Manufacturing (DFM). Often, our recommendations save customers time and money while ensuring that their parts still function as intended. 

Don’t worry—these suggestions aren’t privileged industry secrets. Everyone should know how to optimize their part designs for manufacturing, especially if they plan to transition from prototype to production eventually. 

One piece of advice we frequently give customers is to think critically about their hardware needs.  

4 Tips for Using Hardware More Effectively 

Fasteners, Heli-Coils, dowel pins, and other hardware components are critical in many part designs. These tips will help you make the most effective choices regarding hardware:

1. Keep hardware to a minimum when possible 

Most precision machine shops install hardware post-machining, which can add to a project’s lead time. This consideration is especially important for large orders. 

Depending on the functionality of your part, reducing the amount of hardware in your design may help you get your order faster. 

2. Consider breaking your part into pieces

On the other hand, there are certain times when you’ll want to use some hardware instead of none at all, like if your part could benefit from being machined in two pieces.  

In these cases, it’s quicker for us to machine two pieces and then fasten them together. When in doubt, we can help you decide if this is the right approach, so don’t be afraid to ask.

3. Limit “do not break through” callouts  

We see many drawings with “do not break through” callouts indicating that the hole for the fastener must not go through the entire workpiece. 

While there are certainly times when a through-hole would impede a part’s functionality or aesthetic, we encourage you to consider whether this callout is entirely necessary. Giving your manufacturing partner more flexibility with through-holes can yield time and cost savings.

4. Consider thread depth

Engineers are generally responsible for determining the lengths and thread depths of the screws they request for their parts. What they often don’t realize is that approximately 80-90% of the thread strength is accounted for in the first few threads!

Therefore, when a design indicates that the screw must be run down to 10-15 threads, there’s not much to gain in terms of thread strength. This requirement does, however, add complexity to the manufacturing process, which can increase costs and lead times. So before you request a long screw with significant thread depth, consider whether it’s truly required for your part.

Looking for a precision machining partner who always has your best interests at heart? Request a quote from Armstrong Machining today!