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Material selection determines whether a CNC milled part meets its performance requirements, stays within budget, and can be machined to the required tolerance. This guide compares the four major CNC milling material categories: aluminum alloys, stainless steel grades, titanium, and engineering plastics. Each section covers grade-level differences, cost trade-offs, machinability, and which surface finishes are compatible with each material.

Sourcing aerospace parts CNC machining from China requires the same certification, traceability, and inspection standards as any other supply source. This guide covers how to confirm AS9100 Rev D status in the IAQG OASIS database, what constitutes genuine material mill traceability, which tolerance tiers China factories hold on aerospace features, and how to enforce AS9102 First Article Inspection through the purchase order.

Poor tolerance specification is the leading cause of inaccurate quotes, failed First Article Inspections, and unnecessary rework on CNC milled parts. This guide covers how to specify CNC milling tolerances on a technical drawing, from setting a default ISO 2768 class in the title block to identifying features that genuinely require tight individual callouts. It also covers how surface treatments like anodizing and plating affect fit-critical dimensions, what tolerance tiers China CNC factories actually hold across general, precision, Swiss, and EDM processes, and how each tier drives per-part cost.

ISO 2768 defines general tolerances for machined parts in 4 classes: fine, medium, coarse, and very coarse. This guide covers the full tolerance tables for both Part 1 (linear and angular dimensions) and Part 2 (geometrical tolerances), explains what ISO 2768-mK means on a drawing, compares ISO 2768 to ASME Y14.5, and breaks down the common mistakes engineers make when specifying tolerances.

Learn how 3D printing compares with traditional methods, where it excels, and when it falls short, so you can choose the right process for your next custom part.

Finding the right plastic injection molding company is not just about price . It's about matching your resin, geometry, and certification requirements to a supplier with the verified process capability to deliver consistent parts at volume. This guide covers the five process factors that separate capable suppliers from average ones.

Xometry isn't your only option. We compared 7 manufacturing platforms, pricing models, supplier networks, NDA protection, using data from each company's own site.

CNC machining or 3D printing, which delivers better precision, material strength, and value for your project? Learn the real differences in cost, quality, and scalability. Explore our guide on CNC vs 3D printer and see how you can compare factory quotations directly through Haizol.

How CNC prototype machining works, what it costs ($30-$2,000+), and how to source from verified factories in China. Includes real pricing data, material coverage, tolerance capabilities, and IP protection workflows — backed by Haizol's 2026 analysis of 456 audited factories and 1,118 supplier quotes.