Delrin 525GR: specs and equivalent grades
Delrin USA, LLC acetal homopolymer with 25% glass fiber, formerly DuPont. Published data for 525GR NC000, how the black version differs, grades to ask about, and how to request a quote from one gaylord.
Request a QuoteThe short answer
Delrin 525GR is a 25% glass-reinforced, medium-viscosity acetal homopolymer (POM-H, ISO code POM-GF25) for injection molding. Delrin’s current product database lists it in two colors: 525GR NC000 (natural) and 525GR BK000 (black). For NC000, Delrin publishes MFR 8 g/10 min at 190°C / 2.16 kg, density 1,590 kg/m³, tensile modulus 9,500 MPa, stress at break 160 MPa, notched Charpy 10 kJ/m² and HDT 172°C at 1.8 MPa. That is about three times the stiffness of unfilled Delrin and nearly double its HDT at 1.8 MPa. Flow-direction shrinkage is low (0.4%), but cross-flow shrinkage is 1.2%, so glass orientation matters for flatness. The black version runs slightly lower on flow, strength and flexural modulus. Celanese’s Celcon FG2025 is the only other 25% glass acetal we could match on flow from a producer sheet, and it is a copolymer.
Also written as: Delrin 525GR NC000, Delrin 525 GR, Delrin 525GR BK000, POM-GF25 homopolymer. NC000 is natural and BK000 is black. Delrin is now its own company (an affiliate of TJC holds 80.1% and DuPont 19.9%), so older DuPont sheets still circulate. Quote the full grade and color code from your drawing or bag label.
Buying Delrin 525GR: one gaylord to a railcar · supplier COA on every prime lot · ships from 22+ partner warehouse locations · a polymer chemist checks the grade code before we quote · we aim to quote within one to three business days
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Delrin 525GR specs from the data sheet
Typical values from Delrin USA, LLC’s product database record for Delrin 525GR NC000 (natural), last changed January 27, 2026. Imperial values are from the same record in U.S. units. Typical values are not specifications; the lot COA shows what you actually receive. The black version (BK000) differs on a few rows; see the table below.
| Property | Value | Test method or note |
|---|---|---|
| Producer (brand owner) | Delrin USA, LLC (formerly DuPont) | Delrin is owned 80.1% by a TJC affiliate and 19.9% by DuPont |
| Grade and color | Delrin 525GR NC000 (natural). Also listed: 525GR BK000 (black) | Delrin product database, checked November 6, 2026; status current |
| Polymer | Acetal homopolymer (POM-H), 25% glass reinforced, medium viscosity | Resin ID POM-GF25 (ISO 1043); part marking >POM-GF25< (ISO 11469) |
| Process and form | Injection molding; pellets; contains release agent | Producer record |
| Melt flow | MFR 8 g/10 min | 190°C / 374°F, 2.16 kg, ISO 1133 |
| Density | 1,590 kg/m³ (1.59 g/cm³) | ISO 1183 |
| Tensile modulus | 9,500 MPa (1.38 million psi) | ISO 527-1/-2 |
| Stress at break | 160 MPa (23,200 psi); strain at break 3% | ISO 527-1/-2 |
| Flexural modulus | 9,150 MPa (1.33 million psi) | ISO 178 |
| Flexural strength | 245 MPa (35,500 psi) | ISO 178; producer notes strain at break 3.2% |
| Compressive strength | 210 MPa (30,500 psi) | ISO 604 |
| Tensile creep modulus | 8,500 MPa at 1 h; 6,000 MPa at 1,000 h | ISO 899-1 |
| Charpy notched impact | 10 kJ/m² at 23°C; 10 kJ/m² at -30°C | ISO 179/1eA |
| Charpy unnotched impact | 60 kJ/m² at 23°C; 50 kJ/m² at -30°C | ISO 179/1eU |
| Rockwell hardness | M101; R122 | ISO 2039-2 |
| HDT at 1.8 MPa / 264 psi | 172°C | ISO 75-1/-2 |
| HDT at 0.45 MPa / 66 psi | 176°C | ISO 75-1/-2 |
| Melting temperature | 178°C | ISO 11357-1/-3, 10°C/min |
| Thermal expansion (CLTE) | 35 × 10-6/K parallel; 100 × 10-6/K normal | ISO 11359-1/-2 |
| Thermal conductivity | 0.46 W/(m·K) | ISO 22007-2 |
| RTI (electrical, impact, strength) | 50°C at 0.75, 1.5 and 3 mm | UL 746B |
| Flammability | HB at 1.5 mm and at 0.75 mm; UL recognition listed as yes | IEC 60695-11-10 / UL 94 |
| FMVSS 302 | Class B; burning rate 49 mm/min at 1 mm | ISO 3795 (FMVSS 302) |
| Comparative tracking index | 600 | IEC 60112 |
| Volume resistivity | 1 × 1012 Ω·m | IEC 62631-3-1 |
| Relative permittivity | 3.7 at 100 Hz; 3.8 at 1 MHz | IEC 62631-2-1 |
| Water absorption, 2 mm | 1.26% water absorption; 0.17% humidity absorption | Similar to ISO 62 |
| Molding shrinkage, parallel / normal | 0.4% / 1.2% | ISO 294-4 |
| Drying | 80°C / 176°F for 2–4 h in a dehumidified dryer; processing moisture 0.2% or less | Producer processing data. Delrin says drying is not needed for freshly opened bags stored dry |
| Melt temperature | 210–220°C (410–428°F); optimum 215°C (419°F) | Producer processing data |
| Mold temperature | 80–100°C; optimum 90°C (194°F) | Producer processing data |
| Hold pressure | 80–100 MPa; hold time 8 s/mm of wall | Producer processing data |
| Annealing (optional) | 160°C (320°F), 30 min/mm of wall | Producer processing data |
Typical values; confirm on the current producer data sheet. Source records are listed at the bottom of this page. Confirm against the current sheet for your exact grade code and color.
Grades to ask about instead of Delrin 525GR
We looked for 25% glass acetals with a current producer data sheet and similar flow at the same test condition (190°C / 2.16 kg). Two qualify: the black version of the same grade, and one Celanese copolymer. None is a drop-in replacement: polymer type, glass sizing, color, flow at molding shear rates and approvals differ. If your part, drawing or customer approval names Delrin 525GR, any change needs that approval and a trial.
| Grade | Producer | Melt flow | Density | Key property | How it compares |
|---|---|---|---|---|---|
| Delrin 525GR BK000 | Delrin USA, LLC | MFR 7.5 g/10 min (190°C / 374°F, 2.16 kg, ISO 1133) | 1,590 kg/m³ (ISO 1183) | Tensile modulus 9,500 MPa; stress at break 150 MPa (ISO 527); flexural modulus 8,500 MPa (ISO 178); Charpy notched 10 kJ/m² at 23°C (ISO 179/1eA); HDT 172°C at 1.8 MPa (ISO 75) | Ask about. The black version of the same grade: same polymer, glass level, density, tensile modulus, HDT at 1.8 MPa and shrinkage (0.4 / 1.2%). Delrin lists slightly lower flow (7.5 vs 8), stress at break (150 vs 160 MPa) and flexural modulus (8,500 vs 9,150 MPa), and lower notched impact at -30°C (7.5 vs 10 kJ/m²). Only a fit if black is acceptable on your drawing. Quote this alternative › |
| Celcon FG2025 | Celanese | MFR 7 g/10 min (190°C, 2.16 kg, ISO 1133) | 1,590 kg/m³ (ISO 1183) | Tensile modulus 9,000 MPa; stress at break 160 MPa; strain at break 3% (ISO 527); flexural modulus 8,250 MPa (ISO 178); Charpy notched 8 kJ/m² at 23°C (ISO 179/1eA); melting point 165°C | Check. 25% glass with similar flow and density, but Celcon is Celanese’s acetal copolymer line (melting point 165 vs 178°C). Slightly lower stiffness and notched impact on the sheet; parallel shrinkage 0.7% vs 0.4%. The sheet gives no HDT, so heat performance cannot be compared from it. Celanese lists a cooler mold (60–80°C) and melt (180–210°C). Celanese’s Chemille record lists it as restricted in the Americas and EMEA and available in Asia Pacific, so confirm supply first. Quote this alternative › |
From each producer’s published data. Typical values; confirm on the current producer data sheet. Brand owners and grade names change.
Homopolymer vs. copolymer. Delrin is an acetal homopolymer; Celcon, Hostaform, Kepital and Duracon are copolymers. On these sheets the homopolymer melts about 13°C higher (178 vs 165°C). Copolymers are generally chosen for better hot-water and alkali resistance. See acetal homopolymer vs. copolymer.
Checked but not listed. Celcon GC25T (Celanese, 25% glass-coupled copolymer) has a current sheet: tensile modulus 8,700 MPa, stress at break 125 MPa, HDT 161°C at 1.8 MPa, density 1,580 kg/m³. Celanese publishes no melt flow for it, so we cannot confirm a flow match; ask us if you want it compared on a trial. We did not find Celcon GC25A or plain Hostaform C 9021 GV1/30 in Celanese’s current database. We could not open a producer sheet for Duracon GH-25, Kepital 25% glass grades or Ultraform N2200 G53, so they are not in the table. Delrin 510GR is the same polymer but 10% glass, so it is not an equivalent.
Typical uses for Delrin 525GR
From Delrin USA, LLC’s product database and website:
- Parts that need very high strength and stiffness, high deflection temperature and excellent creep resistance. This is how Delrin describes the grade.
- Hydraulic guide rings: a Delrin case study posted June 10, 2026 charts 525GR with other Delrin grades and says customers select glass-filled Delrin to maximize strength and rigidity.
- Delrin says its acetal resins in general go into automotive, domestic appliance, sports, industrial engineering, electronics and consumer goods parts. That statement covers Delrin as a family, not 525GR alone.
- Parts that need an FMVSS 302 result: the record lists class B with a burning rate of 49 mm/min at 1 mm (ISO 3795).
What to check before you switch
- Owner check: Delrin is no longer a DuPont business. An affiliate of TJC holds 80.1% and DuPont 19.9%. Ask who issues the COA and any compliance letters. See who makes Delrin.
- Color code: Delrin’s database lists 525GR only as NC000 and BK000. The black version has slightly lower flow (MFR 7.5), stress at break (150 MPa) and flexural modulus (8,500 MPa). If your drawing says natural, do not accept black without approval.
- Coming from unfilled Delrin? Delrin 500P (MFR 15), Delrin 100P (MFR 2.5) and Delrin 150 (MFR 2.3) shrink about 1.8–2.2% in the flow direction, per Delrin’s records. 525GR shrinks 0.4% with flow and 1.2% across it. A tool cut for unfilled acetal will not hold size with 525GR, and the reverse.
- Warpage: the gap between flow and cross-flow shrinkage (0.4 vs 1.2%) is typical of glass-filled parts. Gate location and wall design decide how flat a part stays. See warped parts and glass-filled plastics.
- Copolymer alternatives: Celcon FG2025 melts lower (165°C), runs a cooler mold (60–80°C vs 80–100°C) and publishes no HDT. Re-qualify heat, creep and dimensions before you switch. See the acetal buying guide and acetal (POM) properties.
- Heat rating: the record lists RTI 50°C (UL 746B) at 0.75, 1.5 and 3 mm, and HB flammability at 1.5 and 0.75 mm. HDT is a short-term test; it is not a continuous use rating.
- Processing: Delrin lists drying at 80°C for 2–4 h, melt 210–220°C, mold 80–100°C and hold pressure 80–100 MPa. Get the producer’s settings for whatever grade you actually receive. See the resin drying guide.
- Compare melt flow, impact and HDT only at the same test method and condition (ISO and ASTM results differ). Run a trial lot before you switch production.
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Buying Delrin 525GR: price, lead time and lot size
- Lot size. From one gaylord to a railcar. See gaylord, LTL and truckload for typical weights per box.
- Where it ships from. 22+ partner warehouse locations. Lead time is confirmed with your quote, and so are payment terms.
- Price. We do not publish prices because they move with feedstock, freight and order size. What moves your price most: lot size, color code (NC000 or BK000), ship-to region, and whether your approval allows a matched alternative. See how resin is priced and the monthly market update.
- Paperwork. Supplier COA on every prime lot (what a COA shows). Ask for the producer’s compliance letters or UL file if your part needs them.
- Trying an alternative? Start with one gaylord as a trial lot, molded and checked before you commit a full release. Samples (~50 lb) are available upon credit approval.
- Custom color. If you need a color other than natural or black, ask about custom compounding/color.
Send the grade and color code, your annual volume and ship-to location. A polymer chemist reviews every request before we quote. For several grades at once, use the resin RFQ template.
Trade names belong to their owners. ResinBridge is not affiliated with these producers; grade names are used only to identify the material. Data reflects published producer data as of November 2026.
Sources
- Delrin product database, Delrin 525GR NC000 record (SI units), last changed January 27, 2026
- Delrin product database, Delrin 525GR NC000 record (U.S. units)
- Delrin product database, Delrin 525GR BK000 record (SI units), last changed January 27, 2026
- Delrin product database, full grade list (93 grades; 525GR listed as NC000 and BK000), checked November 6, 2026
- Delrin product database, Delrin 500P NC010 record
- Delrin product database, Delrin 100P NC010 record
- Delrin product database, Delrin 150 NC010 record
- Delrin case study: Delrin for hydraulic guide rings, posted June 10, 2026 (delrin.com)
- Celcon FG2025 TDS (Celanese, PDF), revised April 22, 2026
- Celcon FG2025 (Celanese Chemille database; regional availability)
- Celcon GC25T TDS (Celanese, PDF), revised August 12, 2026
- Celcon GC25T (Celanese Chemille database)
- Celanese Hostaform/Celcon acetal copolymer (POM) product page
Common questions
What is Delrin 525GR?
Delrin 525GR is a 25% glass-reinforced, medium-viscosity acetal homopolymer (POM-GF25) for injection molding, made by Delrin USA, LLC. Delrin describes it as having very high strength and stiffness, high deflection temperature, excellent creep resistance and good notched impact. The natural version is 525GR NC000; a black version, 525GR BK000, is also listed.
What is the melt flow of Delrin 525GR?
MFR 8 g/10 min for 525GR NC000 and 7.5 g/10 min for 525GR BK000, both at 190°C / 374°F and 2.16 kg (ISO 1133), per Delrin’s product database. Typical values; confirm on the current producer data sheet.
What is the heat deflection temperature of Delrin 525GR?
172°C at 1.8 MPa and 176°C at 0.45 MPa (ISO 75) for 525GR NC000. That compares with 93°C at 1.8 MPa for unfilled Delrin 500P NC010. The melting point is 178°C for both.
What is the difference between Delrin 525GR NC000 and BK000?
Color, plus small differences in the published data. Both are 25% glass homopolymer with density 1,590 kg/m³, tensile modulus 9,500 MPa and HDT 172°C at 1.8 MPa. BK000 is listed at MFR 7.5 vs 8 g/10 min, stress at break 150 vs 160 MPa and flexural modulus 8,500 vs 9,150 MPa. Quote the color code from your drawing or bag label.
How does Delrin 525GR compare with Delrin 500P?
Delrin 500P NC010 is unfilled. On Delrin’s data, 525GR NC000 has about three times the tensile modulus (9,500 vs 3,100 MPa), a much higher HDT at 1.8 MPa (172 vs 93°C) and far lower flow-direction shrinkage (0.4% vs 2.0%). 500P flows faster (MFR 15 vs 8) and is lighter (1,420 vs 1,590 kg/m³). They are not interchangeable in the same tool.
What is equivalent to Delrin 525GR?
The closest option is the black version of the same grade, Delrin 525GR BK000, if black is acceptable. From another producer, Celcon FG2025 (Celanese) is a 25% glass acetal with similar flow (MFR 7 vs 8), but it is a copolymer with a lower melting point (165 vs 178°C), and Celanese shows Americas availability as restricted. Neither is a drop-in; any change needs your approval and a trial.
Who makes Delrin 525GR?
Delrin USA, LLC. DuPont sold 80.1% of the Delrin business to an affiliate of TJC in 2023 and kept 19.9%. Older data sheets and bags may still say DuPont.
Can ResinBridge quote Delrin 525GR?
Yes. Send the grade, color code and volume. A polymer chemist checks it and we quote Delrin 525GR where we can source it, or a matched alternative, and say which one. Orders start at one gaylord; U.S. and Canada only.
If your grade is not listed, tell us what you run. We source commodity, engineering and specialty resins.
Need Delrin 525GR or an equivalent?
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What to send for an accurate quote
- The grade name, from any supplier, or a data sheet
- Color (natural, black or a custom match)
- Fill type and percentage, if any
- Melt flow, if you know it
- Quantity for this order and what you use in a year
- Ship-to city and state or province
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