What is Delrin? - Kehui Mold Co., Limited

Delrin (also known as POM-H or acetal homopolymer) is a high-performance engineering plastic widely used in precision parts that require strength, stiffness, and low friction. Developed by DuPont and now produced by multiple manufacturers, POM-H is a popular alternative to metals in applications where durability and dimensional stability are critical.

What is Delrin Made Of?

Delrin is a polyoxymethylene (POM) thermoplastic, specifically an acetal homopolymer. Its molecular structure provides:

High crystallinity for strength and rigidity
Excellent resistance to wear and fatigue
Low moisture absorption

Unlike acetal copolymer (POM-C), POM-H has a more uniform structure, giving it better mechanical properties but slightly lower chemical resistance.

Key Properties & Advantages

Property	Benefit
High Strength & Stiffness	Comparable to metals like aluminum in some applications
Low Friction & Wear Resistance	Ideal for gears, bearings, and sliding parts
Excellent Dimensional Stability	Minimal expansion/contraction with temperature or humidity changes
Good Chemical Resistance	Resists fuels, solvents, and weak acids (but not strong acids/bases)
Machinability	Easy to CNC mill, turn, or drill with tight tolerances

Common Applications of POM-H

Automotive: Fuel system components, door handles, seatbelt mechanisms.
Industrial: Gears, bushings, conveyor belts, rollers.
Consumer Goods: Zippers, eyewear frames, power tool housings.
Medical: Surgical instruments, drug delivery devices.
Electronics: Insulating parts, connectors, snap-fit components.

Delrin vs Other Plastics

Delrin (POM-H) vs Acetal Copolymer (POM-C)

POM-H has higher strength and stiffness but lower chemical resistance.
Acetal Copolymer is better for applications requiring hydrolysis resistance (e.g., underwater use).

Delrin vs Nylon (PA)

Delrin has lower moisture absorption and better creep resistance.
Nylon is more flexible and impact-resistant.

Delrin vs PTFE (Teflon)

Delrin is stronger and more rigid but has higher friction.
PTFE is better for extreme chemical resistance and non-stick surfaces.

Machining & Molding Delrin

Machining Tips

Use sharp carbide tools to prevent melting or burring.
Maintain moderate speeds/feeds to avoid excessive heat.
No coolant is typically needed, but compressed air helps clear chips.

Injection Molding Considerations

Melt Temp: 190–210°C (374–410°F).
Mold Temp: 80–120°C (176–248°F) for optimal crystallization.
Drying Required: 2–3 hours at 80°C (176°F) to prevent bubbles.

POM-H is a versatile, high-performance plastic offering an exceptional balance of strength, wear resistance, and machinability. Whether used in automotive gears, medical devices, or consumer products, it provides a reliable, cost-effective alternative to metal.

For precision injection molding or CNC machining of Delrin parts, working with an experienced manufacturer ensures optimal performance and longevity.

Looking for POM-H components? Contact us for expert machining and molding solutions!