How to Machine PEEK – Methods, Tips, Pros & Cons

1. What is PEEK?

PEEK (Polyetheretherketone) is a high-performance engineering thermoplastic known for its excellent thermal resistance, mechanical strength, chemical resistance, and dimensional stability. It's widely used in aerospace, medical, automotive, and electronics industries.

2. Common Processing Methods for PEEK

• CNC Precision Machining

• Suitable for turning, milling, drilling, tapping, etc.

• Ideal for producing high-precision, complex parts

• Injection Molding

• Best for mass production

• Requires high-temperature-resistant molds (melting point ~343°C)

• 3D Printing (FDM)

• Used for prototyping and complex geometries

• Requires a nozzle and build plate >350°C

• Compression Molding / Extrusion

• Common for producing PEEK rods, sheets, and films

3. CNC Machining Tips for PEEK

• Workholding & Deformation Control

• PEEK is softer than metals and can deform under clamping pressure

• Use soft jaws and even pressure to avoid stress marks

• Cutting Parameters

• Use sharp carbide tools, high spindle speed, and low feed rate

• Replace worn tools promptly to avoid burring or melting

• Heat Management & Chip Removal

• Consider cold air cooling for long runs

• PEEK chips tend to stick; keep the cutting area clean

• Dimensional Stability

• Due to thermal expansion, allow time between rough and finish machining (12–24 hrs)

4. Advantages of PEEK

• High heat resistance (up to 250°C+)

• Excellent mechanical strength and creep resistance

• Outstanding chemical and radiation resistance

• Biocompatibility – suitable for implants

• High dimensional stability after machining

5. Disadvantages of PEEK

• High material cost

• Requires high processing temperatures and specialized equipment

• Risk of fine burrs or edge curling during machining
•