---
title: "Delrin & Acetal CNC Machining | POM Precision Parts | OpenSpindle"
description: "Get quotes for custom Delrin and acetal (POM) parts from independent machine shops. Gears, bushings, and low-friction parts machined to tight tolerances. Upload a drawing."
canonical: https://openspindle.com/materials/delrin
---

# Custom Delrin (acetal) parts from independent machine shops

Delrin, DuPont's trade name for acetal (POM), is the go-to engineering plastic for gears, bushings, and low-friction parts. It is stiff, strong, wear-resistant, and machines cleanly to tight tolerances. Upload a drawing and hear back from shops that run acetal every day.

## Delrin shops on OpenSpindle

Real shops that machine Delrin and acetal. See their equipment and talk to the person making your part.

[Browse all Delrin shops](https://openspindle.com/manufacturers?material=Acetal)

## Delrin and acetal grades shops run most

Acetal comes in two base chemistries plus filled variants. The grade sets strength, chemical resistance, and friction; if yours is not here, ask when you request a quote.

### Delrin (POM-H homopolymer)

DuPont's homopolymer acetal. Higher strength, stiffness, and hardness than copolymer, with the best surface finish and creep resistance. Can have a low-density centerline in thick sections. The default when a drawing says "Delrin".

**Best for:** Gears, precision mechanical parts, wear surfaces

### Acetal copolymer (POM-C)

The copolymer grade (Delrin is a homopolymer). Slightly lower strength but better resistance to hot water and strong chemicals, and no centerline porosity, so it is preferred for thick sections and food or medical use.

**Best for:** Thick sections, chemical exposure, food-contact parts

### Delrin AF (PTFE-filled)

Homopolymer acetal blended with PTFE fibers for a much lower coefficient of friction and better wear life. Costs more and is slightly weaker than standard Delrin. The choice for self-lubricating bearing surfaces.

**Best for:** Bearings, bushings, sliding and low-friction parts

### Delrin / acetal, black

Black-pigmented stock, usually UV-stabilized, so it holds up better outdoors and hides handling marks. Mechanically the same as natural. The most common color machined.

**Best for:** Outdoor parts, cosmetic parts, general use

### Delrin / acetal, natural

Unpigmented off-white stock. Mechanically identical to black but not UV-stabilized. Common where color does not matter or a light part is preferred.

**Best for:** Internal parts, general mechanical use

## Material Properties

Representative values for acetal homopolymer (Delrin). Copolymer and filled grades vary slightly.

| Property | Value |
| --- | --- |
| Density | 1.41 g/cm³ (0.051 lb/in³) |
| Tensile strength | ~10 ksi (70 MPa) |
| Max continuous service temp | ~90 °C (195 °F); higher for short peaks |
| Coefficient of friction / wear | Low friction, excellent wear, self-lubricating |
| Chemical resistance | Good vs fuels and solvents; weak vs strong acids and oxidizers |
| Moisture absorption | ~0.2%, dimensionally stable |
| Machinability | Excellent; machines like brass, holds tight tolerances |

Acetal is stiff, strong, and fatigue-resistant, which is why it replaces metal in gears, cams, and small mechanisms. Its low moisture absorption keeps parts dimensionally stable where nylon would swell.

## Stock Forms

- **Plate & block** -- Milled housings, manifolds, and prismatic parts from solid.
- **Round bar** -- Turned gears, bushings, rollers, and spacers.
- **Sheet** -- Routed and cut gaskets, wear strips, and flat parts.

## Processes That Run This Material

- [CNC Machining](https://openspindle.com/capabilities/cnc-machining.md) -- Milled manifolds, housings, and mechanical parts from plate and block.
- [CNC Turning](https://openspindle.com/capabilities/cnc-turning.md) -- Turned gears, bushings, rollers, and fittings from round bar.
- [Swiss Machining](https://openspindle.com/manufacturers?capability=Swiss%20machining) -- High-volume small acetal parts like pins, spacers, and fasteners.
- [Waterjet Cutting](https://openspindle.com/manufacturers?capability=Waterjet%20cutting) -- Cold cutting for flat acetal plate with no heat-affected edge.
- [Laser Cutting](https://openspindle.com/manufacturers?capability=Laser%20cutting) -- Fast flat cuts in thinner acetal sheet for gaskets and wear strips.
- [5-Axis Machining](https://openspindle.com/manufacturers?capability=5-axis%20milling) -- Complex acetal geometry and gear forms in a single setup.

## Finishes

Acetal machines to a fine finish and is almost always shipped as-machined. It does not plate, paint, or anodize, so color comes from the stock, not a coating.

- **As-machined** -- The standard. Delrin cuts to a smooth, low-friction surface straight off the tool, ideal for gears and bearings where a coating would only add drag.
- **Natural vs black stock** -- Choose color at the stock level. Black is usually UV-stabilized for outdoor use; natural is off-white. Both are mechanically identical.
- **Bead blast** -- An even matte texture for a uniform cosmetic look. Optional, since the as-machined finish is already clean.

Skip plating and anodizing questions for acetal. If you need a specific color or UV resistance, call it out so the shop pulls the right stock.

## Applications

- Gears
- Bushings & bearings
- Cams & rollers
- Manifolds & valve components
- Fasteners & clips
- Electrical insulators
- Food-contact parts
- Pump parts

Delrin shows up wherever a stiff, low-friction, dimensionally stable plastic can replace metal.

## How It Compares

How Delrin stacks up against the other engineering plastics and metals shops quote most.

### [Nylon](https://openspindle.com/materials/nylon.md)

- Delrin is stiffer, more dimensionally stable, and has lower friction
- Nylon absorbs far more moisture, so nylon parts swell and lose tolerance in humid or wet use
- Nylon has better impact resistance and abrasion life in some applications

**Verdict:** Choose Delrin for tight-tolerance gears and low-friction parts that must stay dimensionally stable. Choose nylon when impact resistance and toughness matter more than dimensional stability.

### [PEEK](https://openspindle.com/materials/peek.md)

- PEEK handles far higher temperature (continuous ~250 °C vs ~90 °C) and more aggressive chemicals
- Delrin is several times cheaper and machines just as easily
- PEEK is stronger and stiffer, and is used in medical and aerospace parts Delrin cannot reach

**Verdict:** Choose Delrin for cost-effective mechanical parts at moderate temperature. Choose PEEK when high heat, chemical exposure, or strength justify the premium.

### [Aluminum](https://openspindle.com/materials/aluminum.md)

- Aluminum is far stronger and stiffer and handles much higher temperature
- Delrin is lighter, does not corrode, runs quieter, and is electrically insulating
- Delrin is self-lubricating, so it makes better gears and bearings without added lubricant

**Verdict:** Choose Delrin for quiet, low-friction, corrosion-free mechanical parts. Choose aluminum when you need structural strength, stiffness, or heat resistance.

## Frequently Asked Questions

### What is the difference between Delrin and acetal?

Delrin is DuPont's trade name for acetal homopolymer (POM-H); acetal is the generic material, which also comes as a copolymer (POM-C). Homopolymer Delrin is stronger, stiffer, and takes a finer finish, but can have a low-density centerline in thick sections. Copolymer resists hot water and strong chemicals better and has no centerline porosity. Both machine the same, so specify which one if it matters to your part.

### Is Delrin a good material for gears?

Yes, it is one of the most common gear plastics. Delrin is stiff, strong, fatigue-resistant, and self-lubricating with a low coefficient of friction, so gears run quietly and need no added lubricant. Its low moisture absorption keeps tooth geometry dimensionally stable where nylon would swell. For higher loads or temperature, PEEK is the step up.

### Can Delrin be used for food-contact parts?

Acetal is available in FDA-compliant and NSF-listed grades, and copolymer (POM-C) is often preferred for food and medical use because of its chemical resistance and lack of centerline porosity. Compliance depends on the specific stock, not just the material, so note the requirement on your drawing and the shop sources a certified grade.

### Does Delrin absorb moisture like nylon?

No, and that is a key reason to choose it. Acetal absorbs only about 0.2% moisture versus several percent for nylon, so Delrin parts hold their dimensions in humid or wet environments. That stability is why it is preferred for tight-tolerance gears, bushings, and precision mechanical parts.

### What is the temperature limit for Delrin?

Acetal has a continuous service temperature around 90 °C (195 °F) and can handle higher for short peaks. Above that it softens and loses strength. If your part sees sustained high heat or steam, PEEK or a filled high-temperature plastic is the better choice.

### Is Delrin easy to machine?

Very. Acetal is one of the easiest engineering plastics to machine, cutting cleanly much like brass and holding tight tolerances with a fine surface finish. It does not gum up or melt easily with proper feeds and speeds. That machinability, plus its low cost, makes it a favorite for precision turned and milled parts.

### What file formats should I send for a Delrin part?

STEP, IGES, X_T, DWG, DXF, or a dimensioned PDF. Note whether you need homopolymer Delrin or copolymer acetal, the color (natural or black), critical dimensions and tolerances, quantity, and any compliance such as FDA or NSF.

## Related Materials

- [PEEK](https://openspindle.com/materials/peek.md)
- [Nylon](https://openspindle.com/materials/nylon.md)
- [Aluminum](https://openspindle.com/materials/aluminum.md)
- [Stainless Steel](https://openspindle.com/materials/stainless-steel.md)
- [Brass](https://openspindle.com/materials/brass.md)
- [Copper](https://openspindle.com/materials/copper.md)

## Get Delrin part quotes

Upload a drawing once and compare quotes from independent shops that machine Delrin and acetal to tight tolerances.