CNC Machining services
Why use Shapelid for custom online CNC machining services?
Shapelid provides a custom online CNC machining service to engineers, product developers, designers, and more through our vetted network of 10,000+ suppliers. Our highly qualified and certified machine shops can make any custom design, simple or complex. We offer rapid machining, small-batch machining, and high-volume production, with all orders serviced by Shapelid from end to end. Upload a CAD file to the Shapelid Instant Quoting Engine® to get a price, lead time, and design-for-manufacturability feedback on your custom CNC parts. Our fast CNC machining capabilities include services for metals and plastics and flexible production and shipping options to meet you at the perfect price and product development stage. Your price for CNC-machined prototypes includes tariffs and shipping for standard parcels.
Shapelid assures the quality of your machined parts with our ISO 9001:2015, ISO 13485, IATF 16949:2016, and AS9100D certified quality management system, ITAR registration, and options to add inspections, hardware traceability, material certifications, and CoCs. We accept technical drawings and have support teams to ensure you get quality CNC-machined parts on time.
CNC machining tolerances
Feature | Description |
|---|---|
Maximum Part Size | Milled parts up to 80” x 48” x 24” (2,032 x 1,219 x 610 mm). Lathe parts up to 62” (1,575 mm) length and 32” (813 mm) diameter. |
Standard Lead Time | 3 business days |
General Tolerances | Tolerances on metals will be held to +/- 0.005" (+/- 0.127 mm) in accordance with ISO 2768 unless otherwise specified. Plastics and composites will be +/- 0.010”. |
Precision Tolerances | Shapelid can manufacture and inspect to tight tolerances, including sub +/- 0.001" tolerances, per your drawing specifications and GD&T callouts. |
Minimum Feature Size | 0.020” (0.50 mm). This may vary depending on part geometry and chosen material. |
Threads and Tapped Holes | Shapelid can accommodate any standard thread size. We can also machine custom threads; these will require a manual quote review. |
Edge Condition | Sharp edges are broken and deburred by default |
Surface Finish | The standard finish is as-machined: 125 Ra or better. Additional finishing options can be specified when getting a quote. |
CNC Machining Design Guidelines
CNC machining design guidelines help engineers and product designers create parts that are cost-effective, accurate, and easy to manufacture. The first step is to optimize part geometry for machining. Avoid overly complex shapes unless necessary, and design features that can be produced using standard cutting tools. Ensure that walls have a minimum thickness of around 0.8–1.0 mm for metals and 1.5–2.0 mm for plastics to prevent warping or vibration during machining. Using uniform wall thickness also helps maintain structural integrity and reduce machining time.
When designing holes and pockets, match them to standard drill and end mill sizes to reduce tool changes and production costs. For example, hole diameters should typically be larger than 1 mm and have a depth no greater than four times their diameter for best machinability. Sharp internal corners are difficult to machine, so incorporate fillets with a radius that matches standard tool sizes, such as 3 mm, to improve tool access and surface finish. Where possible, design with larger radii to increase cutting tool life.
Material selection is another key factor in CNC machining design. Softer materials like aluminum and plastics machine faster and with less tool wear, while harder materials like stainless steel or titanium require slower speeds and more durable tooling. Choosing the right material for your application impacts both cost and performance. Consider machinability ratings and how the chosen material will interact with cutting tools, surface finish requirements, and post-processing needs.
Lastly, consider tolerances and surface finishes early in the design process. Tight tolerances increase machining time and cost, so specify them only where functionally necessary. For most CNC machined parts, a tolerance of ±0.1 mm is sufficient, but high-precision applications may require ±0.01 mm or better. Similarly, finer surface finishes require additional passes or polishing, which increases production time. By following these CNC machining design best practices, you can reduce manufacturing costs, improve part quality, and ensure efficient production.
