Phenolic (Canvas/Linen)

What Phenolic is

Fabric-reinforced laminate with excellent electrical and mechanical properties.

Why engineers specify it

Phenolic is a thermoset, which is the whole point: it does not soften and flow the way a thermoplastic does as it heats, so it holds its form and its insulating properties at temperatures that would move acetal or nylon. The fabric reinforcement is what separates the grades — canvas is the coarser weave and the tougher, more wear-oriented choice, linen is finer and machines to a better finish for closer work. It is specified where electrical insulation and mechanical duty have to coexist.

Machining Phenolic

Phenolic machines like a composite rather than a plastic, and the fabric reinforcement is abrasive — it dulls tooling noticeably faster than any thermoplastic, so carbide is the sensible default. It cuts dry and produces dust rather than chips, so extraction matters. The failure mode to design around is delamination and edge breakout at the laminate layers: sharp tooling, backing the material where a cutter exits, and easing sharp corners all keep the edges intact.