POM GF25
Reinforced grade
ASTM D4181 · also Delrin
GF25 = 25% glass fiber reinforced
Choose for load-bearing housings, brackets and gears needing high stiffness, low creep and tight dimensional tolerance at elevated temperature.
Values for the GF25 condition
Other POM grades and fills
POM is listed in 10 conditions; see the grade overview at POM.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Impact modified | Select for snap-fits, clips and cold-climate parts needing high notched impact and ductility, at the cost of stiffness and heat resistance. | 43 | 45 | 120 | 70 Shore D |
PTFE-lubricated bearing grade | Use for unlubricated bearings, slides and gears where the lowest friction and wear rate against steel is required. | 45 | 45 | 15 | 78 Shore D |
Carbon-black conductive / antistatic | Pick for fuel-system parts, conveyor and electronics-handling components that must dissipate static charge. | 47 | 48 | 6 | 82 Shore D |
internally silicone-oil lubricated | Cost-effective friction and noise reduction for gears and clips where mechanicals must stay close to unfilled acetal. | 58 | 28 | 79 Shore D | |
Molybdenum disulfide filled | Dark, wear-resistant bearing grade for moderate loads where PTFE cost or FDA compliance is not required. | 58 | 60 | 15 | 82 Shore D |
High-flow / thin-wall injection grade | Use for thin-wall, multi-cavity or long-flow-path parts; higher MFR trades some toughness for fill and cycle time. | 60 | 61 | 20 | 81 Shore D |
Acetal homopolymer | Pick when maximum stiffness, strength, creep and wear resistance are needed and hot alkali/hot water exposure is limited. | 70 | 70 | 30 | 92 HRM |
10% glass fiber reinforced | Modest stiffness and dimensional-stability boost with much lower shrinkage than unfilled, while retaining some ductility. | 85 | 7 | ||
GF25This page 25% glass fiber reinforced | Choose for load-bearing housings, brackets and gears needing high stiffness, low creep and tight dimensional tolerance at elevated temperature. | 130 | 3 | 90 HRM | |
30% glass fiber reinforced | Maximum-stiffness acetal for structural parts; accept brittleness, abrasive wear on tools and strong shrinkage anisotropy. | 135 | 2.5 |
What is POM GF25?
POM GF25 is POM in the GF25 grade — choose for load-bearing housings, brackets and gears needing high stiffness, low creep and tight dimensional tolerance at elevated temperature. POM GF25 has a yield strength of 62 MPa (8.99 ksi) and a tensile strength of 130 MPa (18.9 ksi) — stronger than 72% of polymer grades. Elongation at break is 3% and the elastic modulus is 8.5 GPa (1.23 Msi). POM GF25 has a density of 1.59 g/cm³ (0.0574 lb/in³), heavier than 92% of polymer grades. Its glass-transition temperature is -60°C (-76 °F).
Advantages
- Tough — resists crack growth — 4 MPa·√m (3.64 ksi·√in), better than 92% of polymer grades
- Conducts heat well — 0.36 W/m·K (0.208 BTU/hr·ft·°F), better than 92% of polymer grades
- Stiff — 8.5 GPa (1.23 Msi), better than 91% of polymer grades
- Polishes to a fine finish — 70/100, better than 77% of polymer grades
Limitations
- Heavy — 1.59 g/cm³ (0.0574 lb/in³), worse than 92% of polymer grades
- Limited ductility — 3%, worse than 83% of polymer grades
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
POM GF25 properties
Typical room-temperature values for POM GF25; 15 are specific to this condition. Other listed values are POM reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
POM GF25 has a density of 1.59 g/cm³ (0.0574 lb/in³), heavier than 92% of polymer grades. Its glass-transition temperature is -60°C (-76 °F).
Mechanical17
POM GF25 has a yield strength of 62 MPa (8.99 ksi) and a tensile strength of 130 MPa (18.9 ksi) — stronger than 72% of polymer grades. Elongation at break is 3% and the elastic modulus is 8.5 GPa (1.23 Msi).
Thermal11
POM GF25 is rated for continuous service to 105°C (221 °F). It conducts heat at 0.36 W/m·K (0.208 BTU/hr·ft·°F), better than 92% of polymer grades. Thermal expansion is 40 µm/m·K (22.2 µin/in·°F).
Electrical7
POM GF25 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of POM GF25 takes about 100 MJ of energy and emits 4.5 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 0%.
Manufacturability8
POM GF25's machinability is good (60/100, better than 51% of polymer grades); weldability good (55/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with POM GF25
Is POM easy to machine?
One of the best plastics to machine: sharp positive-rake tools, high speed, light feeds, air or mist cooling; relieve molded-in stress before tight-tolerance finishing and expect springback-free chips.
Can POM be welded?
Hot-plate, ultrasonic, spin and vibration welding all work well; no solvent bonding — adhesive joints require plasma, flame or chromic-acid surface activation.
Can POM be formed, bent or molded?
Dry only if resin is wet (≤0.1%), melt 190–215 °C, mold 80–100 °C, generous gates and full packing; watch ~2% shrinkage, sink and voids in thick sections and never overheat/stagnate melt (formaldehyde release).
What surface finishes work on POM?
Paints and inks need surface pretreatment or special primers; parts polish to a waxy sheen, can be laser-marked, and plating requires a dedicated acetal etch process.
POM chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| ethylene oxide comonomercopolymer (POM-C) only; absent in homopolymer POM-H, which is end-capped instead | 1 – 5 | 2.5 |
| heat/acid stabilizer package (antioxidanessential to prevent depolymerization | 0.2 – 1.5 | 0.6 |
| lubricant / mold release | 0 – 1 | 0.3 |
| pigment (carbon black, TiO2 etc.)carbon black also gives UV protection | 0 – 2 | 0.5 |
| oxymethylene (-CH2O-) repeat unitpolyacetal backbone from formaldehyde/trioxane | ≥ 94 (balance) |
POM GF25 — frequently asked
What is POM GF25 used for?
POM GF25 is typically used for gears, clips and fuel systems. In short: stiff dimensional acetal.
What is the yield strength of POM GF25?
POM GF25 has a typical yield strength of 62 MPa (8.99 ksi) and a tensile strength of 130 MPa (18.9 ksi) — stronger than 72% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is POM GF25 easy to machine?
Reasonably — machinability is rated good (60/100, better than 51% of polymer grades). One of the best plastics to machine: sharp positive-rake tools, high speed, light feeds, air or mist cooling; relieve molded-in stress before tight-tolerance finishing and expect springback-free chips.
Can POM GF25 be welded?
Yes — weldability is rated good (55/100). Hot-plate, ultrasonic, spin and vibration welding all work well; no solvent bonding — adhesive joints require plasma, flame or chromic-acid surface activation.
What surface finishes work on POM GF25?
Paints and inks need surface pretreatment or special primers; parts polish to a waxy sheen, can be laser-marked, and plating requires a dedicated acetal etch process.
Can POM GF25 be formed, bent or molded?
Dry only if resin is wet (≤0.1%), melt 190–215 °C, mold 80–100 °C, generous gates and full packing; watch ~2% shrinkage, sink and voids in thick sections and never overheat/stagnate melt (formaldehyde release).
What is the maximum service temperature of POM GF25?
POM GF25 is rated for continuous use to about 105°C (221 °F), and briefly to 140°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in POM GF25?
Yes — POM GF25 is available for injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Hostaform / Celcon POM copolymer product and processing brochures — Celanese (2023)
- Delrin acetal homopolymer design and molding guides — DuPont / Delrin USA (2022)
- CAMPUS plastics ISO datasets for POM-C and POM-H injection grades — CWFG / CAMPUS consortium (2024)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- ISO 9988 Plastics — Polyoxymethylene (POM) moulding and extrusion materials — ISO (2020)
- ASTM D6100 Standard Classification for Polyoxymethylene (POM) Molding and Extrusion Materials — ASTM (2020)
- Ensinger TECAFORM AH / AD stock shape datasheets — Ensinger (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.