That initial transition from low-volume to high-volume production can initially increase scrap rates, but it can also increase costs and decrease quality for long periods of time. In general, most established shops aim to keep that scrap rate under 5%, with top performers aiming to stay below 2%. That being said, scaling from low-volume to high-volume production can see rework rates up to 15%.
When scaling your production, the wrong machining partner can inadvertently sabotage your margins, timelines, and product quality. The right one? They become an extension of your engineering team—anticipating needs, absorbing complexity, and delivering consistency at scale.
But not all shops are built to support high volumes for precision work. Here’s what to look for when vetting a machining partner that can handle complex geometries and tight tolerances at mass production.
Key Features to Look for in a High-Volume Machining Partner
Machining Envelope
A shop’s machining envelope defines what parts they can physically produce. For milling, this means X/Y/Z travel and spindle clearance. For turning, it’s swing diameter, max length, and live tooling capability. If your part pushes the limits of a shop’s envelope, expect slower setups, more manual intervention, and higher scrap rates.
To give you a real-world example, here is Hirsh Precision’s machining envelope:
Maximum size for milled parts - 41.34" x 22.05" x 18.11" (1,050 x 560 x 460 mm)
Maximum size for lathe parts - Diameter: 26.62" (600 mm) | Length: 29.53" (750 mm)
Identify a shop that not only has the right type of machines to cut your part, but that also has plenty of clearance for your part’s dimensions, which will eliminate the need for repositioning, reduce cycle times, and improve surface finish consistency.
Automated Features
High-volume machining thrives on unattended operation. Shops that run lights-out with barfeeders, pallet changers, and long-cycle programs can amortize setup time across thousands of parts. That’s how you get lower per-unit costs without compromising quality.
At Hirsh, we’ve invested in barfeeders for both our Swiss and multi-tasking machines, like our Okuma Multus B250, as well as more robust automated solutions like our Fastems FMS and FPC systems. These palletized fixtures, powered by the pallet changing hardware and software, allow us to run lengthy cycle times and move a lot of parts through a single operation.
Metrology Capacity
Precision machining is only as good as its inspection throughput. If a shop has one coordinate measurement machine (CMM) and a backlog of parts waiting for first article inspection, your delivery schedule is toast. Look for partners with multiple CMMs, laser scanners, and automated inspection routines integrated into their workflow.
For example, our Quality team maintains a wide range of inspection technology and equipment, including 8 CMMs, multiple styles of visual inspection systems, Z-class gage pins, and in-house calibration for the majority of our hand tools and gages.
If you choose a machining partner with limited metrology capabilities, especially for more complex parts, inspection can quickly become a bottleneck for high-volume production.
Vendor Network
A high-volume machining partner should have a vetted, redundant vendor network for secondary operations that they don’t support in-house, such as anodizing, plating, or wire EDM. That network should also be qualified to the same standards as the primary shop.
In our case, we support several post-machining operations in-house, like passivation and media blasting. For anodizing, plating, black oxide, and other specialty finishing operations that we don’t have in-house, we maintain a vendor network that’s not only redundant (2, 3, and sometimes 4 suppliers deep), but that’s also qualified to our ISO 13485 and AS9100 standards.
Final Thoughts - Making the Leap from Low-Volume to High-Volume Production
High-volume machining isn’t just about cutting a lot of parts—it’s about building a system that scales with your product. Envelope size, automation, metrology, and vendor depth are strategic levers that can get you lower costs, tighter tolerances, and faster deliveries. When they’re not, you get headaches.
You may find that while one shop can support your low-volume production needs really well, they can’t make that jump to the high-volume numbers. When that happens, you’ll likely need to source a new machining partner. Your other option is to identify a partner at the offset who has experience making the leap from low-volume to high-volume production without compromising quality along the way.
So next time you’re vetting a machining partner, don’t just ask what machines they have. Ask how they run them, how they inspect, and how they backstop their promises. That’s how you separate the shops that talk precision from the ones that deliver it.
Amanda White
