The Complete Guide for CNC Part Procurement
Whether you are a buyer, design engineer or project manager — procuring CNC machined parts is a complex task where many factors must be considered. This guide helps you make the right decisions and avoid typical mistakes.
Step 1: Preparing the Enquiry
What Your Manufacturer Needs
A complete enquiry significantly speeds up the quotation process:
- Technical drawing (PDF): With all dimensions, tolerances and surface specifications
- 3D file (STEP): Enables immediate CAM programming
- Material specification: Exact designation (e.g., AW-6082-T6, 1.4301)
- Quantity: Including possible call-off quantities
- Delivery date: Realistic desired date
- Special requirements: Surface treatments, certifications, measurement reports
Step 2: Evaluating the Drawing
Draw Manufacturing-Friendly
Well-designed drawings save costs and time:
- Internal radii: Avoid sharp internal corners — at least R0.5 mm for milling
- Tolerances: Only tolerances tight on functionally important dimensions
- Undercuts: Avoid undercuts where possible
- Wall thicknesses: Maintain minimum wall thickness (aluminium min. 1 mm, steel min. 0.5 mm)
More on cost-influencing factors in our article Cost Factors in Machining.
Step 3: Choosing the Manufacturing Partner
Finding the right partner is the most important decision. Detailed criteria can be found in our articles about:
Step 4: Evaluating the Quotation
What the Price Says — And What It Doesn't
The cheapest quotation is rarely the best. Pay attention to:
- Completeness: Are all services included (material, surface treatment, measurement report)?
- Transparency: Are cost items clearly listed?
- Delivery time: Is the deadline realistic?
- Quality: Are measurement reports and certificates included?
Step 5: Order Placement and Monitoring
Clear Communication
- Confirm all specifications in writing
- Clarify open points before order placement
- Establish a contact person for technical queries
- Agree on milestone communication for larger orders
Frequently Asked Questions (FAQ)
How much lead time for enquiries?
Standard parts typically require 2–4 weeks lead time. For more complex projects or special materials, plan 4–8 weeks. Express production is available at additional cost. Learn about our fast one-off part production: CNC One-Off Parts in 1 Week.
When do I need a measurement report?
A measurement report is recommended for all parts with tight tolerances (IT8 and tighter), safety-critical components and first-off production. For standard parts with general tolerances, a sampling inspection is usually sufficient.
Conclusion: Well Prepared Is Half Won
Professional CNC part procurement requires preparation, clear communication and a reliable partner. With this guide, you are well equipped to source your parts efficiently and at high quality.
First time ordering CNC parts? Contact us — we guide you through the entire process.