CNC-milling plastics demands a different mindset from metal machining. Melting risk, chip evacuation and fixturing all need special attention to achieve crystal-clear edges and stable tolerances. Below is a practical walkthrough with cutting-data guidelines, common pitfalls and material-specific advice—plus how Matenco, with its advanced machine park and 40 years of experience, can handle the entire subcontracting process when you need plastic parts.
Tooling – Use a sharp, polished carbide end mill with a high helix. For Ø ≤ 6 mm, a single- or O-flute works best.
Chip evacuation & cooling – Blow dry compressed air or use minimum-quantity mist. Avoid flood coolant on PMMA and PC to reduce crack risk.
Fixturing – Vacuum table, double-sided tape or soft jaws that spread the load; plastics creep if over-clamped.
Programming – Separate roughing from finishing:
Roughing: high feed, shallow DOC (≤ 0.5 × Ø) to remove heat.
Finishing: half the chipload, leave 0.1–0.2 mm for a glossy surface.
Verification – Always test-cut a sample; plastics vary in filler content, colour and moisture.
Need help? Matenco employs dedicated vacuum fixtures and proprietary O-flute tools in its DN Solutions DVF 5000 and Haas VF-4SS machines—ideal for precision plastic machining.
Cutting speed (Vc) – 250–500 m/min for most thermoplastics: fast enough for clean shearing without melting.
Feed per tooth (fz) – 0.05–0.15 mm/tooth; a thicker chip carries heat away, a thin chip only rubs.
Spindle speed (n) – n = 1000 × Vc / (π × D). Lower Vc, not fz, if the plastic starts to melt.
Spindle overspeed margin – Run roughly 20 % lower rpm than aluminium charts and compensate with higher chipload.
Depth of cut (DOC) – 0.25–0.5 × Ø when roughing, max 0.1 × Ø when finishing; plastics deflect easily at deep cuts.
Width of cut (WOC) – 40–60 % of Ø for stable chip breaking without chatter.
Example: ABS, Ø 6 mm, 2-flute carbide: Vc ≈ 300 m/min → n ≈ 16 000 rpm. With fz = 0.08 mm, feed ≈ 2 550 mm/min.
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Below is a practical overview of cutting speeds, feeds, tools, and other key parameters for milling plastics—drawing on our extensive experience and trusted industry guidelines.
Cutting speed (Vc): 300–500 m/min
Feed (fz): 0.05–0.12 mm/tooth
Depth of cut (ap): 0.25–0.5 × Ø roughing, ≤ 0.1 × Ø finishing
Tool: Polished carbide, high helix, single- or O-flute
Cooling: Dry air or minimum mist
Tips: Clamp gently—ABS shrinks; climb-milling leaves a glossy edge
Cutting speed (Vc): 280–500 m/min
Feed (fz): 0.08–0.15 mm/tooth
Depth of cut (ap): 0.25–0.5 × Ø roughing, ≤ 0.1 × Ø finishing
Tool: Positive-rake carbide, 2–4 flutes
Cooling: Dry air or light mist
Tips: Use chipload toward the upper range to minimise burr
Cutting speed (Vc): 250–380 m/min
Feed (fz): 0.06–0.12 mm/tooth
Depth of cut (ap): 0.25–0.5 × Ø roughing, ≤ 0.1 × Ø finishing
Tool: Single-flute spiral, polished edge
Cooling: Strong, dry air blast
Tips: Program lift moves and vacuum extraction to manage stringy chips
Cutting speed (Vc): 280–500 m/min
Feed (fz): 0.07–0.15 mm/tooth
Depth of cut (ap): 0.25–0.5 × Ø roughing, ≤ 0.1 × Ø finishing
Tool: Sharp carbide, positive helix
Cooling: Dry air or water-based mist after conditioning
Tips: Balance moisture content before machining for tight tolerances
Cutting speed (Vc): 180–300 m/min
Feed (fz): 0.05–0.10 mm/tooth
Depth of cut (ap): 0.25–0.4 × Ø roughing, ≤ 0.05 × Ø finishing
Tool: Polished O-flute for optical finish
Cooling: Dry air or water-mist only
Tips: Leave ≈ 0.1 mm stock; final pass with a fresh edge for crystal-clear faces
Cutting speed (Vc): 250–350 m/min
Feed (fz): 0.05–0.12 mm/tooth
Depth of cut (ap): ≤ 0.25 × Ø per pass
Tool: High-helix, sharp carbide
Cooling: Air cooling—avoid petroleum coolants
Tips: Corner radius ≥ 1 D reduces crack risk; avoid IPA cleaning immediately after milling
Cutting speed (Vc): 280–500 m/min
Feed (fz): 0.05–0.12 mm/tooth
Depth of cut (ap): 0.2–0.4 × Ø roughing, ≤ 0.08 × Ø finishing
Tool: Polished carbide with razor-sharp edge
Cooling: Dry machining with high-efficiency vacuum
Tips: Low friction—secure fixturing and chip vacuum prevent back-slip
Cutting speed (Vc): 250–350 m/min
Feed (fz): 0.05–0.12 mm/tooth
Depth of cut (ap): 0.25–0.4 × Ø roughing, ≤ 0.1 × Ø finishing
Tool: Coated carbide (e.g. TiAlN) for abrasive fibres
Cooling: Water-mist or dry air with vacuum
Tips: Reduce rpm ≈ 20 % for glass-filled grades; inspect edge wear frequently
Industry leaders turn to Matenco for plastic machining because its advanced machine park—featuring a DN Solutions DVF 5000 five-axis center, a Haas VF-4SS and automated Fanuc Robodrill cells—secures short lead times and outstanding repeatability. Matenco assumes full responsibility from raw stock through grinding and polishing to the finished component, giving customers a single, accountable partner. More than a vendor, the company treats each challenge as its own, continually verifying, adjusting and delivering to meet exact requirements. Backed by forty years of proven experience and a customer base that keeps coming back, Matenco has earned a reputation for reliable quality and competitive cycle times. Whether you already have drawings or just an idea, simply send your CAD files or request a free consultation—Matenco will turn your plastic parts from concept to series production with confidence and efficiency.
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