What is CNC milling?

What is CNC milling?

CNC milling is a manufacturing process where raw materials are carved and sculpted into shapes to produce a finished product. This is accomplished by using a computer to control the motion of a machine tool. The machine tool can be a cutting tool like a drill, router, or laser or a drilling machine like a milling machine.

CNC milling positions raw material between the cutting tool and anvil, the anvil moving vertically to be parallel with the cutting tool. The machine operator instructs the computer to make preparations for the desired product. They usually give the length, width, and height of the desired object. After the cutting tool moves to the particular point in space in relation to the table surface spindle, the computer moves the table to the next point in space for programming the next cut. The computer then sends a stream of data to the machine, which moves the cutting tool to the desired location. A brush removes any swarf as it is being produced.

The first operation of a CNC mill generally is to rough out the corners with a to break loose the material as well as to ensure that the table will be flat. The next steps may involve leveling the table and doing bevels and chamfers to the edges. The ight side is done by using a right-handed tool. The left side will be done by using a left-handed tool. The operator can specify on the milling machine how much material to remove, often set to three-eighths of an inch. The machine operator can choose to use a left or right-handed tool, depending on the purpose of the end product. However, left-handed tools are used to mill a right side and vice versa, they move the end product's direction by 180 degrees.

The process of CNC milling is often considered to be efficient due to its ability to remove excess material while ensuring the shape of the object. It also ensures that the object is level. While the machining process has limitations on the types of materials, many materials can be CNC milled. The grading system for determining strength of a material is used to determine the best tool for the material. The cnc milling process is also used to create objects that are more complicated than can be done by hand. It will produce pockets, holes, and slots of precise size and shape.

PartzPro Frequently Asked Questions

The "Open-Book" Business Model

Q: Why is there a factory invoice in the box?
That is your Commercial Import Invoice. Because we ship Factory Direct to your door, international customs requires an invoice that travels with the package.
  • Transparency & Compliance: This invoice lists the origin factory (showing you exactly who made your parts) and declares the exact value you paid at checkout.
  • Why it matches your payment: We ensure the commercial invoice matches your transaction value so that Customs calculates your duties correctly and legally, preventing delays or penalties at the border.
Q: Why don't you offer Instant Quotes?
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.
Q: If I have the factory’s info, why shouldn't I just go direct next time?
First, strictly speaking, you cannot. To protect our platform, our Terms of Use include a Non-Circumvention clause that prohibits direct transactions with our suppliers for 24 months.

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.
Q: What exactly does your Service Fee cover?
Your fee covers Financial Security (Escrow), Vendor Vetting, AI Engineering Analysis, and Project Management. We act as your US-based legal firewall. We find the best factories, negotiate the rates, and hold the money until the job is done right.

Logistics, Customs & AI Technology

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.

Quality Assurance & Liability

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.
Q: What happens if the parts arrive out of spec?
You are protected by the PartzPro Escrow Guarantee. Because we hold the funds, the factory does not get paid until you verify the order.

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.

Payments & Corporate Orders

Q: We are a company, not a hobbyist. Can we pay via Purchase Order (PO)?
Yes. We specialize in serving agile engineering departments and mid-sized manufacturing firms.
  • How to order with a PO: You can select "Pay via PO / Wire" at checkout or email our sales team directly with your PO attached. We will verify your company details and send a payment link or wire instructions immediately so production isn't delayed.
Q: Do you offer Net-30 Terms?
We offer terms to qualified business partners after an initial credit review. Please contact our sales team to set up your corporate account. For new customers, we recommend using our PO-to-Wire workflow for the fastest start.

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Please be advised that the content presented on our blog and throughout our website is intended strictly for informational purposes. It is designed to serve as a preliminary guide and reference point for our customers embarking on their projects. We endeavor to provide insightful and useful information, but it is imperative for each individual and organization to undertake their own comprehensive research and assessment before making any decisions related to their designs or component usage.Our blog and website content should not be considered as a replacement for specialized advice suited to your unique requirements. For more detailed terms and conditions, kindly refer to our Terms of use. The responsibility for the application of any information obtained from our blog or website in your designs, applications, or parts usage, rests solely with you, the reader or user. Our goal is to inform, advise, and inspire; however, the ultimate application and use of this information is under your discretion and liability.