Acetal copolymer (POM-C). Excellent dimensional stability, low friction, outstanding wear resistance. Standard for precision gears, bushings and bearings.
POM-C (Polyoxymethylene copolymer, Acetal copolymer) per ISO 9988-1 is a semi-crystalline thermoplastic known for its outstanding combination of: (1) high stiffness and strength, (2) excellent dimensional stability (low and consistent water absorption), (3) low coefficient of friction and excellent sliding wear resistance, (4) good fatigue resistance. POM-C (copolymer) has better chemical resistance and easier processing vs POM-H (homopolymer, Delrin). Standard material for precision gears, bearings, bushings, cams and sliding elements in mechanical engineering.
| Standard Body | Designation | Country / Region | Note |
|---|---|---|---|
| ISO | POM-C (ISO 9988-2) | International | |
| EN | EN ISO 9988 | EU | |
| ASTM | D4181 (POM) | USA | |
| Trade Names | Hostaform C (Celanese) / Ultraform N2320 (BASF) / Celcon M90 (Celanese) / Delrin 150 (DuPont, copolymer variant) | Global | |
| Key Grades | POM-C natural / POM-C black / POM-C+PTFE (self-lubricating) / POM-C+GF25 | Global | |
| UL | 94 HB (standard); V-2 (FR grade) | USA | |
| FDA | 21 CFR 177.2470 (food contact) | USA | |
| JUS | PL-POM-C | Yugoslavia | Polioximetilen kopolimer |
| RoHS | Compliant | EU |
| # | Standard Body | Designation | Country / Region | Note |
|---|---|---|---|---|
| 1 | ISO | POM-C (ISO 9988-2) | International | — |
| 2 | EN | EN ISO 9988 | EU | — |
| 3 | ASTM | D4181 (POM) | USA | — |
| 4 | Trade Names | Hostaform C (Celanese) / Ultraform N2320 (BASF) / Celcon M90 (Celanese) / Delrin 150 (DuPont, copolymer variant) | Global | — |
| 5 | Key Grades | POM-C natural / POM-C black / POM-C+PTFE (self-lubricating) / POM-C+GF25 | Global | — |
| 6 | UL | 94 HB (standard); V-2 (FR grade) | USA | — |
| 7 | FDA | 21 CFR 177.2470 (food contact) | USA | — |
| 8 | JUS | PL-POM-C | Yugoslavia | Polioximetilen kopolimer |
| 9 | RoHS | Compliant | EU | — |
| Element | Symbol | Min % | Max % | Typical % |
|---|---|---|---|---|
| Carbon (POM copolymer) | C | — | — | 39.8000 |
| Hydrogen | H | — | — | 6.6600 |
| Oxygen | O | — | — | 53.2000 |
| Water absorption (eq. 50% RH) | H2O | — | 0.2000 | — |
| Condition | Code | Rm min MPa | Rm max MPa |
Re min MPa | Re max MPa |
A₅ min % |
Z % |
KV J |
HB min | HB max | HRC min | HRC max | E GPa |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| POM-C (standard copolymer) | STD | 60 | 72 | 55 | 65 | 20.0 | — | — | — | — | — | — | 2.8 |
| POM-C GF25 | GF25 | 100 | 135 | 85 | 110 | 3.0 | — | — | — | — | — | — | 8.0 |
| POM-C PTFE (self-lubricating) | SL | 55 | 65 | 48 | 58 | 12.0 | — | — | — | — | — | — | 2.5 |
| Coolant | Dry cutting ONLY — NO water or water-soluble coolants |
| Chip Formation | Short chips; good chip control; very clean machining |
| Tool Material | Carbide K10; HSS M2 acceptable; very sharp tools |
| Surface Finish | Ra 0.1-0.8 um — excellent surface finish |