CNC precision metal parts are components machined by computer-controlled cutting tools to dimensional tolerances that cannot be reliably achieved by conventional fabrication alone. According to Fundamentals of Modern Manufacturing (Groover, 5th ed., Wiley), CNC machining centres routinely achieve positional accuracies of ± 0.005 mm – ± 0.01 mm in controlled thermal environments, making them indispensable for aerospace, medical, semiconductor, and high-performance automotive applications.
Jiafeng's CNC department operates 1 five-axis machining centre, 2 four-axis machining centres, 2 CNC lathes, and 11 CNC milling centres — all housed alongside our sheet metal manufacturing and electromechanical integration lines for full vertical integration.
Tolerance values follow ISO 286-1 (limits and fits) and ISO 2768-1 (general tolerances). ±0.005 mm positional accuracy on 5-axis centres is consistent with published Heidenhain TNC 640 controller specifications and ISO 230-2 (machine tool accuracy testing).
| Equipment | Qty | Work Envelope | Positional Tolerance | Surface Roughness Ra | Suitable Metal Parts Materials |
|---|---|---|---|---|---|
| 5-Axis Machining Centre | 1 | φ 2 – φ 26 mm | ± 0.005 mm | Ra 0.4 – 0.8 µm | Steel, aluminium, copper, titanium, Inconel |
| 4-Axis Machining Centre | 2 | φ 2 – φ 20 mm | ± 0.008 mm | Ra 0.8 – 1.6 µm | Steel, aluminium, engineering plastics |
| CNC Lathe | 2 | Up to φ 200 mm | ± 0.01 mm | Ra 0.8 – 1.6 µm | Steel, stainless steel, aluminium, brass |
| CNC Milling Centre | 11 | 2 050 × 500 × 400 mm | ± 0.02 mm | Ra 1.6 – 3.2 µm | All metals, composites |
| 5-Face CNC Centre | — | 1 000 × 500 × 400 mm | ± 0.01 mm | Ra 0.8 – 1.6 µm | Steel, aluminium, Invar |
Corrosion protection ratings follow ISO 9227 (neutral salt-spray test). Film thickness values reference ISO 2177 (electrolytic coating measurement) and EN 13438 (powder coating on steel).
| Finish | Film / Layer (µm) | Salt-Spray Hrs (ISO 9227) | Hardness Gain | Colour Options | Recommended Metal Parts Use |
|---|---|---|---|---|---|
| Powder Coating | 60 – 120 | 500 – 1 000 | Moderate | RAL / custom | Enclosures, cabinets, chassis |
| Zinc Electroplating (blue/white) | 5 – 25 | 96 – 128 (Jiafeng line) | Slight | Clear, yellow chromate | Fasteners, brackets, connectors |
| Anodising Type II | 5 – 25 | 300 – 500 | Moderate | Clear, black, gold, custom | Aluminium metal parts, panels |
| Hard Anodising Type III | 25 – 80 | 1 000 + | High (300–500 HV) | Natural, black | Aerospace, defence, wear surfaces |
| Passivation (citric / nitric) | — | 1 000 + (SS) | None | Natural SS | Medical, food-grade stainless metal parts |
| Brushing + Clear Lacquer | 5 – 15 | 100 – 200 | None | Natural / satin | Consumer electronics, decorative panels |
The word "precision" has no legal definition in manufacturing — it only gains meaning when referenced to a specific standard. Jiafeng applies the following benchmarks to every production order:
| Standard | Scope | Applied At Jiafeng |
|---|---|---|
| ISO 2768-1 (f / m / c / v) | General linear and angular tolerances for machined metal parts | Default drawing note where individual tolerances are not specified |
| ISO 286-1 (H7 / h6 etc.) | Limits and fits for cylindrical features | Shaft / bore fits on turned and bored metal parts |
| ASME Y14.5-2018 / ISO 1101 | Geometric dimensioning and tolerancing (GD&T) | All drawings with form, profile, or position callouts |
| ISO 6892-1 (tensile testing) | Tensile strength and yield strength of metallic materials | Material certification verification on incoming raw stock |
| ISO 4288 / ISO 1302 | Surface texture measurement and indication | Ra / Rz callouts on machined surfaces; CMM stylus measurement |
What is the tightest tolerance you can hold on CNC metal parts?
On our 5-axis machining centre, positional accuracy of ± 0.005 mm is achievable under controlled thermal conditions (20 °C ± 1 °C per ISO 1 temperature standard). Critical medical and aerospace metal parts are machined with climate-controlled fixturing.
Can you machine titanium or Inconel metal parts?
Yes. Our 5-axis centre supports titanium alloys (Ti-6Al-4V) and nickel superalloys (Inconel 625, 718) using carbide and CBN tooling with high-pressure coolant. Consult our engineers for speeds, feeds, and expected cycle times on exotic material metal parts.
Do you provide first-article inspection reports (FAIRs) for metal parts?
Yes. First-article inspection reports covering all drawing dimensions, including GD&T callouts, are produced using our CMM (E = 1.9 + 3L/1000 µm). Reports can be provided in AS9102 or customer-specific format.
What is the lead time for prototype precision metal parts?
Prototype lead time is typically 5–10 business days after drawing approval. Complex 5-axis metal parts may require 10–15 days. Production scheduling for repeat orders follows agreed call-off windows.
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