POM / Acetal.
The precision-machining engineering plastic, tight tolerances, low friction, food-grade in the right formulation.
Where precision and stability matter .
POM (polyoxymethylene), often called acetal or by the brand name Delrin®, is the precision-machining engineering plastic. Tighter dimensional tolerances than nylon, lower friction, better fatigue resistance, food-grade in the right formulation. We CNC-machine acetal for gears, cams, valve stems, food-processing components and any application where precision and stability are non-negotiable.
Highly crystalline engineering thermoplastic with excellent dimensional stability, very low friction, good fatigue resistance and a hard, slick surface. Density ~1.41 g/cm³. Service temperature -40°C to +90°C. Not hygroscopic, holds dimension where nylon moves with humidity. Can be machined to ±0.025 mm.
Homopolymer acetal (Delrin®), slightly stronger, slightly higher centerline porosity. Copolymer acetal (Hostaform®, Acetron®), more chemical-resistant, more dimensionally stable, no centerline porosity. We'll specify by application, copolymer for chemical and food, homopolymer for high-load mechanical.
The specs at a glance.
Common applications .
Precision gears, cams, valve components and timing parts where dimensional stability matters and lubrication is impractical. Food-grade copolymer acetal for processing equipment.
Where nylon's moisture absorption causes dimensional drift, acetal holds. That makes it the right choice for precision-fit assemblies, valve seats and any application where fits matter.
- Precision gears and cams
- Valve stems and seats
- Conveyor chain components
- Bearing components
- Food-processing precision parts
- Pump impellers (low-pressure)
- Custom machined assemblies
- Lab equipment components
From sheet to finished part .
CNC machining for precision parts. Drilling, tapping, threading, profiling and 3D milling to tight tolerances. Standard tooling, fast feed rates, clean chips. Bonds poorly, design for mechanical assembly.
Stocked natural, black and food-grade acetal copolymer in 5 to 80 mm sheet, 10 to 200 mm round bar. Homopolymer (Delrin®) brought in to order. Glass-filled and PTFE-filled grades to spec.
Keep exploring .
Common questions about acetal .
Delrin® is the most common brand name for homopolymer acetal (POM-H). Generic copolymer acetal (POM-C, brand names include Hostaform® and Acetron®) is more chemical-resistant, more dimensionally stable and has no centerline porosity. We stock copolymer as standard, homopolymer to order.
Acetal holds dimension where nylon moves with humidity, it's not hygroscopic. So for precision-fit valve seats, gears, cams and any application where fits matter, acetal is the right choice. Nylon is tougher and cheaper, but acetal is more stable.
Up to ±0.025 mm achievable with standard CNC tooling. Acetal machines fast and clean, with crisp edges and a hard, slick surface, it's one of the most pleasant engineering plastics to machine.
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