How We Achieve +/- 0.001” or Better Tolerances at Our Prototype Machine Shop

Since opening the doors to Summit CNC, we’ve developed a reputation for superior prototype CNC machining services.

There are many factors that set us apart from other prototype machine shops. However, one that’s especially important to our customers is our ability to consistently achieve tolerances of +/- 0.001” or less.

5 Factors That Help Us Achieve +/- 0.001” or Better Tolerances

Not every part requires such tight tolerances. Our standard tolerances are +/- 0.005”, but we’re happy to machine precision tolerances upon request.

Here are five factors that help us deliver parts with precision tolerances every time.

Class Z gage pins used to inspect holes and slots with precision tolerances.

1. World-class Milling and Turning Centers

Many shops offering prototype machining services use lightweight machines, but not us. We have exceptionally heavy mills that weigh up to 30% more than many lightweight or more economical mills on the market. 

The mass and rigidity of our CNC machines provide a more stable foundation that is ideally suited to achieving tight tolerances. The machines vibrate minimally, so parts remain firmly in place during precision machining.

We currently use Doosan mills and lathes and are one of the first shops in our area to use their high-speed S-series machines. We’re committed to continuously improving and advancing our technologies and are always looking for the best equipment that will enable us to deliver on our promises to our customers.

2. Superior Look-ahead

We only buy mills with high-speed machining capabilities that provide superior look-ahead planning functionality.

Our mills analyze data during the precision machining process and automatically adjust feed rates to ensure parts are made to spec. The machines know to optimize for accuracy, rather than speed, on tight tolerance features.

Analyzing data and adjusting feed rates in real time allows us to achieve tight tolerance features while minimizing programming and machining times. We pass this time and cost savings onto our customers.

3. Hydraulic Chuck Tool Holders

Our commitment to embracing innovation and using world-class equipment extends to every facet of our precision machining processes—even tool holding. 

We use hydraulic chuck tool holders on all of our end mills. Compared to ER collets and other tool holders, hydraulic chuck tool holders provide maximum surface contact with the cutting tool, ensuring the rigidity needed to maintain tight tolerances on even the most challenging features. 

4. Tool Wear Optimization

We always use tool wear settings on our machine tool controllers. 

Our machines are programmed to ensure that the tools used for finishing tool paths account for wear, so that feature tolerances are never compromised. This approach reduces our internal tooling costs, which helps keep costs reasonable for our customers. 

5. Mastercam Implementation

There are many CAM software options to choose from, but at Summit CNC, we exclusively use Mastercam to program all of our customers’ parts. 

In contrast to less advanced CAM software often used in prototype machine shops, Mastercam gives us full control over how programmers approach customers’ parts, taking their specific requirements into consideration. That control allows us to dial in programming quickly and effectively, which translates to better costs and lead times for our customers. 

We’re not the only shop offering prototype CNC machining services and making high-quality parts, but we’re confident when we say that we achieve some of the tightest tolerances out there.

If you’re seeking a prototype machining partner who can deliver parts requiring precision tolerances down to +/- 0.001” or less, you can trust Summit CNC. Request a quote today, and let us show you what we can do.