Machining Guide

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
Minimum tolerance for small dimensions 0.05mm

For more detailed information, Dotmar is pleased to provide comprehensive technical guides courtesy of our supplier Quadrant EPP.