Polycarbonate

What Polycarbonate is

Virtually unbreakable with excellent optical clarity and impact resistance.

Polycarbonate or acrylic

This is almost always the decision, and the two materials fail in opposite directions. Polycarbonate takes an impact that would shatter acrylic, which is why it goes into guarding, glazing and anything a person could walk into. Acrylic is harder, holds a polish better and resists scratching and weathering, which is why it wins on signage and display where nothing is going to hit it. If the part protects someone, specify polycarbonate. If it has to stay looking new outdoors, look at acrylic first.

Machining Polycarbonate

Polycarbonate is tough rather than hard, and it softens at the cut rather than chipping — dull tooling or too little chip load melts and smears the edge instead of cutting it. Sharp tools, positive rake and enough feed to keep the chip moving are what give a clean edge. It is also notch-sensitive and holds moulding stress, so generous internal radii matter and annealing before finishing is worth the time on parts that have to stay flat. Solvent choice deserves care around machined polycarbonate: not every cleaner is safe on a stressed part, and the wrong one crazes edges days after the part ships.