3240 EPOXY BOARD CNC MACHINING
Professional 3240 Epoxy Glass Cloth Laminate Machining - High-Quality Electrical Insulation Parts for Motor, Transformer and Switchgear Applications
PROTOREV is a professional 3240 epoxy board CNC machining manufacturer, serving global clients in the electrical, power transmission, industrial equipment, and machinery sectors. We specialize in precision machining of 3240 epoxy glass cloth laminates (GB/T 1303.1 standard) - delivering tight tolerances, clean edge quality, and consistent dimensional stability from prototype to mass production.
3240 epoxy board is a B-class insulating material made from woven alkali-free glass cloth impregnated with epoxy resin, pressed under heat and pressure. It is widely used in China and internationally for electrical insulation structures, motor components, transformer parts, switchgear insulation, and precision mechanical supports. Its characteristic yellow/orange color makes it easy to identify in assembly lines.
Why Choose 3240 Epoxy Board for CNC Machining
Excellent Electrical Insulation
High dielectric strength and arc resistance - ideal for high-voltage insulation parts, busbar supports, and electrical switchgear components.
High Mechanical Strength
Superior flexural and compressive strength ensures structural reliability under mechanical load and vibration in motor and transformer assemblies.
High Temperature Resistance
B-class insulation rating with long-term service temperature up to 130 degree C, short-term tolerance up to 155 degree C - suitable for demanding thermal environments.
Good Moisture & Chemical Resistance
Low water absorption and resistance to common industrial oils and solvents - maintains insulation performance in humid and mildly corrosive environments.
Superior Dimensional Stability
Minimal thermal expansion and warpage after machining - critical for precision insulation spacers, terminal blocks, and mating parts in electrical assemblies.
Cost-Effective & Readily Available
3240 is a mature, widely stocked industrial material with competitive pricing - ideal for medium-to-high volume production of electrical insulation parts.
3240 Epoxy Board - Technical Properties
- Electrical Insulation: Dielectric strength >= 14 kV/mm - provides reliable high-voltage insulation for transformers, switchgear, and motor assemblies.
- Flexural Strength: >= 340 MPa - maintains structural integrity under mechanical load, vibration, and thermal cycling.
- Insulation Class: B-class (130 degree C long-term) - suitable for most industrial electrical and power equipment applications.
- Low Water Absorption: <= 0.5% (after 24h immersion) - retains insulation properties in humid environments and outdoor installations.
- Flame Resistance: Self-extinguishing behavior (non-flaming grade) - meets general industrial safety requirements for electrical insulation parts.
3240 Epoxy Board - Full Specification
| Property | 3240 Epoxy Board (GB/T 1303.1) |
|---|---|
| Standard | GB/T 1303.1 (China National Standard) |
| Base Material | Woven alkali-free glass cloth + epoxy resin |
| Color | Yellow, orange, or reddish-brown (characteristic) |
| Insulation Class | B-class (130 degree C long-term service) |
| Dielectric Strength (vertical) | >= 14 kV/mm |
| Flexural Strength (perpendicular) | >= 340 MPa |
| Compressive Strength | >= 350 MPa |
| Water Absorption (24h) | <= 0.5% |
| Density | 1.7 to 2.0 g/cm3 |
| Available Thickness | 0.5mm - 50mm+ (custom thickness on request) |
| Sheet Size | 1020x2020mm / 1220x2440mm (standard); custom cut-to-size available |
| Flame Resistance | Non-flaming / self-extinguishing (meets GB/T 1303 test) |
How Does CNC Machining 3240 Epoxy Board Work
1CAD Design & Toolpath Programming
Your CAD drawings are converted into optimized CNC toolpaths - accounting for the abrasive glass fiber content and ensuring clean edge quality on the characteristic yellow laminate.
2Tool Selection & Workpiece Setup
Tungsten carbide or diamond-coated tools are selected to resist the abrasive glass fibers. The yellow epoxy board is firmly clamped with backing support to prevent chipping and delamination during cutting.
3Precision Milling, Drilling & Tapping
CNC operations are performed at controlled spindle speeds with coolant or air blast - producing precise holes, slots, and profiles with minimal burr and heat-affected zones.
4Deburring, Inspection & Packaging
All edges are deburred, parts are visually and dimensionally inspected against drawings, then securely packaged for domestic or international shipment.
Machining Tolerances & Capabilities
| Specification | PROTOREV Capability |
|---|---|
| CNC Machining Tolerance | +/-0.05mm (+/-0.002") standard; +/-0.01mm (+/-0.0004") achievable for precision fitting parts |
| Minimum Wall Thickness | 1.0mm (recommended); 0.8mm achievable with careful setup |
| Minimum Hole Diameter | 0.6mm (drilling); 0.8mm (through-hole with clean exit) |
| Surface Finish (as machined) | Ra 1.6 to 3.2 um; edge deburring and light polishing available |
| Maximum Part Size | 1000 x 600mm (dependent on machine worktable) |
| Material Thickness Range | 0.5mm to 50mm (single layer); laminated stacking available for thicker parts |
| Typical Lead Time | 3 to 7 working days for prototypes; 7 to 15 days for production batches |
| File Formats Accepted | PDF, DWG, DXF, STEP, IGES, SolidWorks, AutoCAD |
Common Applications for 3240 Epoxy Board CNC Parts
- Motor & Generator Insulation: Slot wedges, phase insulation, end laminations, and commutator spacers for electric motors and generators.
- Transformer & Switchgear: Insulation spacers, busbar supports, terminal blocks, and arc barriers for oil-immersed and dry-type transformers.
- Electrical Control Cabinets: Insulation mounting plates, relay bases, and DIN rail mounting panels for industrial control systems.
- Power Transmission Equipment: High-voltage insulation parts, circuit breaker components, and switch panel insulation boards.
- Industrial Machinery: Jigs, fixtures, precision spacers, and wear-resistant non-conductive structural components.
- New Energy Equipment: Insulation parts for EV charging stations, battery pack insulation, and solar inverter components.
CNC Machining Tips for 3240 Epoxy Board
Use Carbide or Diamond-Coated Tools: The alkali-free glass cloth reinforcement in 3240 is abrasive. HSS tools dull quickly - use tungsten carbide or diamond-coated end mills and drill bits for clean cuts and longer tool life.
Control Spindle Speed & Feed Rate: Optimal spindle speed for 3240 is typically 8000-15000 RPM for milling, with moderate feed rates. Excessive speed generates heat that can soften the epoxy matrix; too-slow feed causes burning and poor edge quality.
Use Coolant or Compressed Air: Continuous air blast or water-soluble coolant clears glass fiber dust and suppresses heat buildup. This prevents delamination at the cut edge and extends tool life significantly.
Support the Workpiece Properly: 3240 epoxy board is brittle under point loads. Use a backing board (sacrificial layer) underneath when drilling or through-cutting to prevent exit-edge chipping and delamination.
Dust Extraction & PPE: Machining 3240 generates fine glass fiber and cured epoxy dust. Use industrial dust extraction at the cutting point and wear PPE (goggles, gloves, P95/N95 respirator) in a well-ventilated workspace.
Why Choose PROTOREV for 3240 Epoxy Board CNC Machining
- Specialized in 3240 & Composite Insulation Materials: Extensive experience machining 3240 epoxy board, G10, FR4, and other glass-reinforced laminates - we understand material behavior and optimal cutting strategies.
- Carbide Tooling & Optimized Feeds: Our CNC machines are equipped with carbide and diamond-coated tooling specifically for abrasive glass-fiber composites - delivering clean edges, tight tolerances, and superior surface finish.
- Full In-House Production: From CNC milling, drilling, and tapping to custom cut-to-size, chamfering, and silk-screen marking - complete production in-house with no outsourcing delays.
- Strict Dimensional Inspection: Every batch is dimensionally inspected against your drawings. We provide inspection reports and can issue first-article inspection (FAI) reports on request.
- Flexible Order Quantities: From single-piece custom prototypes to medium-volume production runs (5 to 5,000+ pcs) - competitive pricing at every scale with no minimum order quantity.
Our Advantages
One-stop Service
Our strong in-house production capabilities ensure you receive exactly the finished part you need.
Quick Response
24 hours prompt response, 4 to 24 hours for quotation, 5 to 7 days for prototype.
Quality Assurance
Complete testing equipment; Issue test report for each batch of parts before shipment.
Professional Service
Flexible transportation (DHL, FedEx, UPS, air or sea); Production progress updated at any time.