Basic Machining Tips for Engineering Plastics

• Keep heat to a minimum and ensure heat build-up in the part is avoided.
• Keep tools sharp at all times.
• Ensure that only the cutting edge contacts the material.
• Apply coolants (per guidelines) where heat is generated.
• The lower rigidity of plastics may require support or plugging to avoid deflection in thin walled sections.
• Cutting tools should be high speed steel or carbide tipped for production runs, especially on graphite or glass filled materials.
• Matching Tolerance

• It is much larger than for metal
• Watch stress relieving where a large body of material is removed.
• Thermal conditioning may be required after pre-machining on some parts.
• Allow a tolerance of 0.1-0.2% of nominal size.
• Be aware of thermal expansion in larger parts or panels where fixings are required.
• Refer “Solutions” on this website.
• Minimum tolerance for small dimensions 0.05mm.

For more detailed information, please contact us for more comprehensive technical guides.