Archive: Apr 2024

Grinding at Peerless Precision: Our Secret to High-Precision Parts

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At Peerless Precision, we frequently make parts with such tight tolerances and complex geometries that our customers think we’re using a bit of “black magic.”

And while our team loves the aura of mystery this brings to our Westfield, MA machine shop, we must admit: it’s not magic that allows us to create such impressive parts—it’s our in-house grinding capabilities.

Almost every part we create at Peerless Precision goes through our grinding department, allowing us to achieve tolerances and part dimensions that aren’t possible with CNC machining alone.

For example, while our 5-axis machines can achieve tolerances of +/-0.005” inches, our customers often need parts with an even higher degree of precision. Thanks to our in-house grinding capabilities, our MA machine shop can achieve tolerances as tight as +/-0.0001” -0.000005” and surface finishes down to a mirror-like 2 Ra.

It’s no wonder our customers think there is a touch of wizardry in our production processes!

Our In-House Grinding Capabilities


There are two primary types of grinding we perform at Peerless Precision.

  1. Surface grinding allows us to grind surfaces to a certain flatness or achieve a specified surface finish. When we take parts off a CNC machine, the best-case scenario is that parts will have a 32 Ra finish. At this Ra value, parts will feel gritty, and you’ll be able to see imperfections on the material’s surface. Surface grinding allows us to smooth out these imperfections and accomplish a shiny, mirror-like 2 Ra finish.
  2. Cylindrical hole grinding can entail grinding a part’s inner diameter (ID) or outer diameter (OD). We also offer jig grinding, which allows us to perform both of these operations at once! In most cases, we use cylindrical grinding to achieve greater precision–particularly when multiple parts need to fit together as part of an assembly.

While most of our grinding machines are numerically controlled, some human interaction is required. The one notable exception is jig grinding, which is a 100% manual process. Only the most experienced operators and machinists are capable of performing the necessary manual machining to execute grinding processes flawlessly.

A Commitment to Manual Machining

Even as technology advances, Peerless Precision remains as committed to manual machining today as we did when our Westfield, MA, machine shop opened its doors 48 years ago. Blending CNC machining with traditional manual machining has allowed us to thrive–and is what makes it possible for us to offer in-house grinding capabilities to our customers. In fact, we’ve become the go-to shop for other area manufacturers who don’t have the internal expertise needed to grind parts themselves.

We’re proud to have about 100 years of combined grinding experience in our tight tolerance machine shop. And although a few of our longest-tenured employees are nearing retirement, we have planned ahead by placing 60 percent of our new hires in our manual machining department, where they can learn from some of the best in the industry.

This commitment to training ensures that when these valued long-time team members decide to move on, their decades of experience and knowledge are passed down to the next generation–and that we maintain the talent needed to continue offering these valuable services to our customers for the long haul.

Your One-Stop Shop for Tight-Tolerance Parts

If you’ve ordered tight tolerance parts from Peerless Precision in the past, those parts most likely made their way through our grinding department–whether you realized it or not! Grinding isn’t a service you have to ask for; rather, it’s something we do automatically to ensure we meet your complex part requirements.

By remaining committed to providing these services in-house, we retain full control over the quality of your parts, meaning you can count on us to deliver high-quality parts that meet your requirements each and every time.

That’s where the real magic lies.

Request a quote to experience the Peerless Precision difference for yourself!

We Supply Parts To:

  • Curtis Wright
  • FLIR
  • Kaman
  • Curtis Wright
  • FLIR
  • Kaman