Design considerations for CNC machined parts

Design considerations for CNC machined parts

Traditional machining has evolved over the years, giving way to an era of more complex machining systems that are cost-effective and highly efficient. Computer numerical control (CNC) machining is a subtractive process of manufacturing that utilizes an automated power that is computer-integrated to control tools such as lathes, boring, and drilling machines. It is used to produce parts of high quality with high dimensional accuracy in a cost-effective manner. There has been tremendous growth in the use of CNC machining, thereby revolutionizing the manufacturing industry. As such, this technology has reduced the human resources required in the production of sophisticated parts as the machines can work on a large number of work-pieces for mass production. This way, the consumer’s demands are easily met over a short period of time while at the same time producing high-quality products.

CNC machining process
A design is first drafted using computer-aided design (CAD) and loaded into the CNC machine that interprets the design into special codes. The material, which is often a block work-piece, is then placed in the CNC and clamped in position. The work-piece is then machined automatically following the design fed into the CNC computer.

Design consideration for CNC machining
The design for CNC machining parts is quite flexible but often limited by the capability of a particular CNC machine and its tooling. Designers are therefore required to adhere to specific requirements for the successful production of high-quality parts. Parts tolerance is an essential consideration in design for parts to be machined in CNC as such tight tolerances may lead to unwanted costs due to an increase in scrap, the requirement of specialized tools, and fixtures. Therefore standard tolerances should be applied based on the type of material to be machined. Tight tolerances should only be used in critical design requirements.

The size of the material blank is another factor of interest during design. It is recommended that the size of the blank be 0.125 inches larger than the actual dimensions of the part to be machined. This will ensure that the part dimensions are retained even after machining.

The type of material is considered a vital driver that determines the overall cost of the component. The material type has a significant impact on the overall price of the part based on the geometry and the size of the component. Designers should consider cheaper material of the design that doesn’t warrant the material properties of a material that is more expensive. The wall thickness of the part to be manufactured plays a crucial role in determining the overall strength of the region to be machined. Designers should avoid too thin walls or too thick walls in their designs as they limit the part’s structural integrity. Undercuts should also be considered in the design. Undercuts results when some features of the part to be machined are unbelievable. Undercuts with non-standard dimensions may require additional special tools to create a custom feature, which results in the additional cost of producing a part.

Conclusion
To sum up, CNC machining offers numerous benefits in manufacturing, such as high dimensional accuracy of the part to be produced. However, designers should be careful when designing parts to be machined in a CNC machine to produce high-quality parts.

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That is your Commercial Import Invoice. Because we ship Factory Direct to your door, international customs requires an invoice that travels with the package.
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Because "Instant" usually means "Inaccurate." Competitors use algorithms to guess the price based on geometry averages. This often leads to:
  • The "Bait & Switch": They quote low instantly, then email you 24 hours later to raise the price once a human actually looks at it.
  • The "Risk Buffer": They inflate the price by 30% just to cover the errors their algorithm makes.
We measure twice, cut once. We have the factory validate the CAM strategy before we give you a price. You wait a few hours, but the price you get is the price you pay—guaranteed. No surprises.
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But practically, clients stay for the "US Shield." When you order through PartzPro, your money is held in US-based Escrow. We handle the legal leverage, language barriers, and financial security. If you go direct, you lose that protection and have zero recourse if something goes wrong.
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Q: Who handles the HTS Codes and Customs paperwork?
Our AI does the heavy lifting; you just confirm the release. We don't leave you guessing on complex government tariffs.
  • Heavy AI Analysis: Our proprietary AI Assistant performs a 40-point analysis of your part's geometry and material. It automatically searches the official US Government HTS database to generate a precise HTS Code Breakdown for your specific parts.
  • The Process: This data is provided to the carrier (DHL/FedEx/UPS). When the broker contacts you, the classification is already estimated—you simply confirm it to release the shipment.
Q: Who pays the duties?
You do—which saves you money. Because we ship DAP (Delivered at Place), you pay the exact duties owed to the government based on the AI-generated HTS code.
  • Why this is better: Competitors who offer "Free Shipping/DDP" often inflate the price to cover the worst-case tariff scenario. By paying the actual duties yourself, you ensure you are never overcharged for import taxes.
Q: How fast is shipping?
Since we skip the "Middleman Warehouse," our standard international shipping is extremely fast (typically 3–5 days transit). Your parts fly directly from the machine shop to your desk.

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Q: Competitors inspect parts at a US warehouse before shipping. Why don't you?
Because "double handling" kills speed and adds unnecessary cost. We operate on a "Dock-to-Stock" model. The factory performs the rigorous QC, and parts ship directly to you.

We treat you like a professional: we know you will verify the fit and function of your parts upon arrival. By removing the redundant middleman inspection, we save you 30% on cost and 3–5 days on lead time.
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The Process: You have a 3-Day Inspection Window upon delivery to verify fit and function. If parts are non-conforming, simply upload a photo and inspection report within that window. We will either force an immediate priority remake at the factory’s expense or issue a refund.

*Bulk Order Extension: For large volume orders, this inspection window can be extended. To request an extension, simply reply to your automatic invoice email.
Q: Does your AI just check for geometry errors?
No. Our AI Cost-Driver Audit goes beyond simple DFM (Design for Manufacturing). It helps you perform Value Engineering by highlighting features that are disproportionately expensive (e.g., deep pockets, tight radii, non-standard threads). We show you the cost drivers so you can engineer the price down before you order.

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