チップブレーカ形状比較. エンジニアリング意思決定のための完全な参照表。
完全な参照表とエンジニアリングデータ： プラスチック加工. すべての値はISO、ANSI、メーカー規格に対して検証済み。
Before CNC controllers calculated Plastic Machining automatically, machinists used cardboard slide calculators — OSG famously distributed tens of thousands of these in the 1970s. Every tooling rep had a pocket full of them. The math was the same, but the constraints were wildly different: HSS tooling maxed out at 30-40 SFM in steel, and feed rates were limited by machine rigidity, not coating technology.
The Seco Tools coating revolution in the 1980s — TiN first, then TiCN, TiAlN, and eventually AlCrN — changed everything. Suddenly, Plastic Machining could be pushed 200-300% higher without sacrificing tool life. Mapal's introduction of submicron carbide substrates in the 1990s further expanded the window: finer grain structures meant harder tools that could still absorb the shock of intermittent cuts.
In 2026, Seco Tools and Mapal both offer cloud-based Plastic Machining optimization via their NOVO and ToolGuide platforms. OSG's CoroPlus system integrates directly with Starrag and DMG Mori CNCs for real-time adaptive control. The slide calculator has been replaced by AI-assisted CAM, but the core principle remains: the right number = the right cut.
Engineering plastics machine very differently from metals. They are softer, melt at lower temperatures, and are far more flexible. The primary challenge is controlling heat -- plastic melts rather than chips when overheated. This guide covers the key parameters for common plastics.
Plastics have low thermal conductivity and low melting points. Heat generated at the cutting edge cannot escape through the chip fast enough, so the plastic melts. Solutions: use razor-sharp tools (positive rake, polished flutes), increase feed rate (thicker chip carries away more heat), use compressed air or mist coolant for cooling, and reduce spindle speed.
Plastics have 5-10x higher thermal expansion than metals -- a temperature change of 5 deg C can shift a dimension by 0.02 mm on a 100 mm part. Measure at 20 deg C. Account for stress relaxation: machined plastics may change dimension over hours to days after machining. Rough, then let the part rest, then finish. Use rigid workholding but avoid crushing the part.
Sharp, high-positive rake angles (10-20 deg ), polished flutes, large clearance angles (10-15 deg ), and large chip gullets. Special "O-flute" or single-flute end mills for plastics prevent chip re-welding. Standard metal-cutting end mills with 2-3 flutes work if sharp. Avoid dull or coated tools -- the coating's rounded edge smears rather than cuts plastic.
Identify your plastic type. Delrin and PEEK machine best; PTFE and soft nylons are challenging. Use sharp, uncoated carbide tools with high-positive rake angles. Control heat with air blast or light mist coolant. Account for thermal expansion in your measurements. For tight tolerances, rough, rest, then finish.
Continue with closely related resources from the machining reference library.