Precision CNC Machining for FR4 – High-Strength Electrical Insulation Parts
FR4 is a glass‑reinforced epoxy laminate known for its excellent electrical insulation, high mechanical strength, and good heat resistance. It is the standard material for PCB substrates, test fixtures, and structural electronic components. At Ranglink, we specialize in CNC machining of FR4 for prototypes and production runs – from simple spacers to complex test jigs and insulator plates.
– Outstanding dielectric strength (20–40 kV/mm).
– High mechanical strength (tensile > 300 MPa).
– Low moisture absorption and excellent dimensional stability.
– Good machinability with carbide tools (though abrasive).
– UL94 V‑0 flame retardant rating.
Key Properties of FR4 (Glass Epoxy)
| Property | Value / Rating |
|---|---|
| Dielectric strength (short time) | 20–40 kV/mm |
| Volume resistivity | 10¹⁴ – 10¹⁵ Ω·cm |
| Dielectric constant (1 MHz) | 4.2–5.2 |
| Tensile strength (longitudinal) | ≥ 300 MPa |
| Flexural strength | ≥ 400 MPa |
| Compressive strength | ≥ 400 MPa |
| Water absorption (24h) | ≤ 0.10% |
| Thermal class (max operating temperature) | 130°C (Class B) / 155°C (Class F on request) |
| Flammability | UL94 V‑0 |
| Density | 1.85–1.95 g/cm³ |
Our CNC Machining Capabilities for FR4
| Parameter | Specification |
|---|---|
| Max part size (milling) | 1100 × 600 × 500 mm |
| Max turning diameter | Ø230 mm (FR4 typically milled, not turned) |
| Standard tolerance | ±0.05 mm |
| Precision tolerance | ±0.005 mm (on request) |
| Surface roughness (as machined) | Ra 1.6 μm (edge finishing optional) |
| Lead time (prototypes) | 3 business days |
Processes available: CNC Milling (3‑axis, 4‑axis) · CNC Drilling · Routing · Profile cutting · CNC Turning (limited)
Surface Treatment & Post-Processing for FR4
Note: FR4 does not require special surface treatment for most electrical insulation applications. For outdoor use, apply conformal coating or UV‑resistant paint.
Common Applications of CNC Machined FR4
Quality Assurance
- ISO 9001:2015 certified – audited quality management system.
- Full traceability – material certificates and inspection reports.
- Inspection equipment – CMM, calipers, micrometers, optical comparators.
- Every part inspected – ensuring dimensional accuracy, edge quality, and no delamination.
Why Choose Ranglink for FR4 CNC Machining?
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