Custom Bakelite (Phenolic) CNC Machining Services in China
Machining High-Performance Thermoset Components for Superior Heat and Electrical Resistance.
- ISO 9001 Certified
- Excellent Electrical Insulator
- High-Temperature Stability
Your Expert Partner for Bakelite Machining
Celerity Precision is a specialized manufacturer in China offering expert CNC machining of Bakelite (Phenolic Laminates). Bakelite is a high-performance thermoset plastic, created by impregnating layers of a base material (like paper or canvas) with a phenolic resin and curing it under high pressure and heat. The result is an extremely hard, rigid, and dense material renowned for its outstanding performance as an electrical insulator and its ability to withstand high temperatures. From terminal boards and switchgear to high-temperature jigs and fixtures, machining Bakelite is a specialized process due to its hardness and abrasive nature. Our facility is equipped with the right tooling and expertise to machine this durable material to your precise specifications.
Why Choose Bakelite for Your Machined Parts?
Bakelite is the material of choice when you need a rigid, dimensionally stable component that can provide reliable electrical insulation, especially at elevated temperatures where thermoplastics would melt or fail. Unlike thermoplastics, thermosets like Bakelite do not melt when heated; they maintain their structural integrity until they char at very high temperatures. This makes them exceptionally reliable for safety-critical insulating applications. At Celerity Precision, we use specialized diamond-coated and carbide tooling to machine the hard and abrasive grades of Bakelite, managing the fine dust produced to create parts with a clean, smooth finish and sharp, precise details.
Excellent Electrical Insulator
One of the best and most widely used materials for high-voltage electrical insulation.
High-Temperature Resistance
Retains its strength and rigidity at high continuous operating temperatures.
High Strength & Rigidity
An extremely hard, stiff, and creep-resistant material that will not bend or deform under load.
Excellent Dimensional Stability
Low thermal expansion and zero moisture absorption ensure parts hold tight tolerances.
Good Chemical Resistance
Resistant to a wide range of common solvents and weak acids.
Lightweight
Significantly lighter than ceramic or metallic insulators, offering a good strength-to-weight ratio.
Paper-Based Phenolic (X/XX/XXX Grades)
This is the most common grade for electrical applications. It offers the best insulating properties and is relatively easy to machine to a smooth finish. It is typically brown or black.
| Tensile Strength, Yield (MPa) | 125 MPa (Grade XX) |
| Dielectric Strength (V/mil) | 500 V/mil |
| Max. Temp. (Continuous) | 125°C (257°F) |
| Density (g/cm³) | 1.35 |
Canvas-Based Phenolic (C/CE Grades)
The addition of a cotton canvas laminate provides significantly higher mechanical strength and impact resistance than paper grades, making it better for structural parts like gears and wear pads.
| Tensile Strength, Yield (MPa) | 75 MPa (Grade C) |
| Dielectric Strength (V/mil) | 200 V/mil |
| Max. Temp. (Continuous) | 125°C (257°F) |
| Density (g/cm³) | 1.36 |
Linen-Based Phenolic (L/LE Grades)
A fine-weave linen fabric laminate provides a smoother machined finish than canvas grades, making it ideal for intricate, high-precision mechanical parts like small gears.
Surface Finishing Options for Bakelite
Bakelite is a functional material that is not suitable for secondary finishing.
As Machined
This is the only finish available. Bakelite machines to a very clean, smooth, and hard surface. The finish reveals the layered, laminated nature of the material, especially on side profiles. The standard color is a dark brown or black.
Pros and Cons of Bakelite CNC Machining
Pros
- Superior Electrical Insulator: The top choice for high-voltage terminal boards, switch components, and insulators.
- Performs in High Heat: Will not melt or deform at high temperatures, providing excellent reliability.
- Extremely Rigid & Stable: Holds its shape and dimensions perfectly under mechanical and thermal load.
- Strong and Durable: A hard, dense material that is resistant to wear and abrasion.
Cons
- Very Abrasive to Machine: The laminated structure is very hard on cutting tools, requiring specialized (carbide or diamond) tooling and increasing machining costs.
- Brittle: Has low impact strength and can chip or crack if dropped or subjected to sharp impacts.
- Produces Abrasive Dust: Machining produces a fine, abrasive dust that requires a powerful and effective dust collection system for safety and machine longevity.
- Cannot be Glued or Welded: As a thermoset, it cannot be solvent-welded. Bonding requires mechanical fastening or specialized industrial epoxies.
Applications of CNC Machined Bakelite Parts
Electrical & Electronics
Terminal boards, insulators, switch panels, coil forms, and mounting plates.
Industrial Machinery
Jigs and fixtures for welding or soldering, where high heat is present.
Mechanical Components
Gears, pulleys, and wear pads (canvas and linen grades).
Aerospace
Insulating components for electrical systems.
Automotive
Gaskets, seals, and insulating components for older or specialized vehicles.
Prototyping
Creating rigid, heat-resistant prototypes for testing.
Bakelite Machining FAQ
What is the main difference between Bakelite (a thermoset) and a thermoplastic like PEEK?
A thermoplastic (like PEEK) can be re-melted and re-formed. A thermoset (like Bakelite) undergoes an irreversible chemical change when cured. It will not melt; it will only char at very high temperatures. This gives thermosets superior stability at high temperatures.
Why is Bakelite a good electrical insulator?
Its chemical structure does not contain free electrons, which prevents the flow of electricity. It has high dielectric strength and low electrical conductivity.
What is the difference between paper, canvas, and linen grades?
The base material determines the properties. Paper provides the best electrical insulation. Canvas provides the highest impact strength and durability. Linen provides the best combination of strength and a smooth machined finish for fine details.
Is Bakelite difficult to machine?
Yes, it is very hard and abrasive. It requires very sharp, hard cutting tools (like carbide) and is machined “dry” without liquid coolants. Effective dust collection is mandatory.
Can Bakelite be used in a wet environment?
It has good moisture resistance, but over long periods, the cut edges of the laminate can slowly absorb moisture. For very humid applications, a sealant is sometimes recommended.
What color is Bakelite?
The most common and natural color is a dark, reddish-brown. Black is also a very common standard color.
Is Bakelite a strong material?
It has excellent compressive strength and is very rigid, but it is also brittle and can crack under sharp impacts.
Why do you machine it "dry"?
The laminate base (paper, canvas) can absorb liquid coolants, which can cause the material to swell and delaminate. Machining is performed dry with a high-volume air blast and vacuum system to clear chips and dust.