Victrex PEEK 450G: specs and equivalent grades
Victrex unfilled, semi-crystalline PEEK in standard flow: melt viscosity 350 Pa·s at 400°C, Tg 143°C, melting point 343°C, for injection molded and extruded parts. Published data, grades from other producers to ask about, and how to request a quote from one gaylord.
Request a QuoteThe short answer
PEEK 450G is Victrex’s general-purpose, unfilled, semi-crystalline polyetheretherketone (PEEK) for injection molding and extrusion, supplied as natural/beige granules. Victrex describes it as a standard-flow, general-purpose grade. The March 2026 data sheet lists melt viscosity 350 Pa·s at 400°C (ISO 11443), density 1.30 g/cm³ (ISO 1183), glass transition 143°C (onset), melting point 343°C, HDT 152°C at 1.8 MPa (ISO 75) and tensile stress at yield 98 MPa (ISO 527); Victrex’s product page adds an MFR of 8.5 g/10 min at 380°C / 5 kg (ISO 1133). These are typical values; confirm on the current producer data sheet. Unfilled PEEK from other producers to ask about includes Syensqo KetaSpire KT-820 NT and Evonik VESTAKEEP L 4000 G. They are matched alternatives, not identical, so compare the data sheets and qualify with a trial before switching.
Also written as: 450G, PEEK 450G, Victrex 450G or VICTREX PEEK 450G. Victrex sells related versions as separate grades, for example 450G MIC (micropellets for compression molding), 381G (depth filtered, for specialty extrusion), 150G and 90G (higher flow), 450GL30 (30 % glass fiber) and 450CA30 (30 % carbon fiber). Quote the full code and color from your drawing or bag label; suffixes change the grade.
Buying PEEK 450G: 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
Have a part number or drawing callout?
Paste it as written. A polymer chemist will tell you which grade it calls for, suggest equivalents and quote it by email.
PEEK 450G specs from the data sheet
Typical values from Victrex’s data sheet for VICTREX PEEK 450G (Victrex PDF, revised March 2026), with melt flow and crystallinity from Victrex’s 450G product page. Typical values; confirm on the current producer data sheet. Typical values are not specifications; the lot COA shows what you actually receive. Values only compare at the same test method and condition.
| Property | Value | Test method or note |
|---|---|---|
| Producer (brand owner) | Victrex | |
| Polymer | Polyetheretherketone (PEEK), unreinforced, semi-crystalline; natural/beige granules | |
| Process | Injection molding and extrusion; Victrex calls it standard flow | |
| Melt viscosity | 350 Pa·s | 400°C, ISO 11443 (Victrex product page gives the shear rate as 1000 s-1) |
| Melt flow | MFR 8.5 g/10 min | 380°C / 716°F, 5 kg, ISO 1133 (Victrex product page) |
| Density | 1.30 g/cm³ (crystalline) | ISO 1183 |
| Mold shrinkage, flow / across flow | 0.90 % / 1.3 % | ISO 294-4; 375°C nozzle, 190°C tool |
| Water absorption, saturation, 23°C / 100°C | 0.45 % / 0.55 % | ISO 62 |
| Tensile modulus, 23°C | 4,000 MPa | ISO 527-1 |
| Tensile stress at yield, 23°C | 98 MPa | ISO 527-2 |
| Tensile strain at break, 23°C | 25 % | ISO 527-2 (the product page comparison table lists 45 %) |
| Flexural modulus / stress at yield, 23°C | 3,800 MPa / 165 MPa | ISO 178 |
| Flexural stress at 125°C / 175°C / 275°C | 85 / 19 / 12.5 MPa | ISO 178 |
| Compressive stress, 23°C / 120°C | 125 MPa / 70 MPa | ISO 604 |
| Charpy notched impact, 23°C | 7.0 kJ/m² | ISO 179/1eA |
| Notched Izod impact, 23°C | 6.0 kJ/m² | ISO 180/A (the product page lists 8.0 kJ/m²) |
| Glass transition temperature | 143°C / 289°F onset; 150°C midpoint | ISO 11357-2 |
| Melting temperature | 343°C / 649°F | ISO 11357-3 (the product page comparison table lists 339°C) |
| Crystallization temperature / typical crystallinity | 290°C / 35 % | ISO 11357 (Victrex product page) |
| HDT 1.8 MPa, unannealed | 152°C / 306°F | ISO 75-2/Af |
| Coefficient of thermal expansion, average | 55 ppm/K below 143°C; 140 ppm/K above 143°C | ISO 11359-2 |
| Relative temperature index | 260°C electrical; 240°C mechanical without impact; 180°C mechanical with impact | UL 746B, as listed on the data sheet |
| Flammability | Glow wire flammability index 960°C at 2.0 mm. The data sheet does not list a UL 94 rating; ask for the UL file if your drawing needs one. | IEC 60695-2-12 |
| Dielectric strength / CTI | 23 kV/mm at 2.0 mm / 150 V | IEC 60243-1 / IEC 60112 |
| Sterilization | The data sheet describes 450G as suitable for steam sterilization | As stated on the sheet |
| Drying | 150°C / 302°F for 3 h or 120°C / 248°F for 5 h; max moisture 0.02 %; hopper below 100°C | Producer processing data |
| Barrel / nozzle temperature | Rear 355°C, middle 360–365°C, front 370°C, nozzle 375°C (671–707°F) | Producer processing data |
| Mold temperature | 170–200°C (338–392°F) | Producer processing data |
| Runner and gate | Nozzle above 3 mm, manifold above 3.5 mm; gate above 1 mm or 0.5 × part thickness | Producer processing data |
| Food contact | The 450G data sheet does not include a food-contact statement. Victrex’s 450G product page points to separate food grades that may be more suitable. Ask Victrex for a regulatory statement for the exact grade and color before any food-contact use. |
Source data sheets are listed at the bottom of this page. Where Victrex’s product page and data sheet differ (strain at break, notched Izod, melting point), the table uses the data sheet and notes the other value.
Victrex says the mold surface, not just the set point, must hold 170–200°C to avoid quench-cooling PEEK into the amorphous state. Amorphous areas look brown; properly crystallized PEEK looks beige. Victrex suggests electric heaters for smaller parts and oil heaters with isolated flow lines for larger shots or tools with deep cores.
PEEK 450G vs 150G, 381G and the filled 450 grades
Victrex sorts its unfilled PEEK by melt viscosity: lower viscosity means easier flow and lower molecular weight. The filled 450 grades add glass or carbon fiber. All values from Victrex data sheets and the 450G product page; typical values; confirm on the current producer data sheet.
| Grade | Fill | Melt viscosity, 400°C | Density | How it differs from 450G |
|---|---|---|---|---|
| 90G | Unfilled | 90 Pa·s | 1.30 g/cm³ | Very easy flow, depth filtered, for injection molding complex parts with thin sections or long flow lengths. Tensile stress at yield 105 MPa; notched Izod 4.0 kJ/m² (ISO 180/A), lower than 450G. |
| 150G | Unfilled | 130 Pa·s; MFR 75 g/10 min (380°C, 5 kg) | Not listed in the comparison | Higher flow, lower molecular weight. Victrex says it suits thin walls, intricate parts, fiber impregnation and highly filled compounds, with slightly higher stiffness and strength but lower toughness (notched Izod 5.0 vs 8.0 kJ/m² and crystallinity 39 vs 35 % in Victrex’s comparison table). |
| 381G | Unfilled | 300 Pa·s | 1.30 g/cm³ | Depth-filtered granules for specialty extrusion: wire coating, filaments, minitubes and films. Same listed tensile values and HDT as 450G; notched Izod 5.4 kJ/m². |
| 450G | Unfilled | 350 Pa·s | 1.30 g/cm³ | This grade. Standard flow for general injection molding and extrusion. |
| 450GL30 | 30 % glass fiber | 550 Pa·s | 1.51 g/cm³ | Built on the 450 base for higher strength in static parts. Tensile modulus 11,500 MPa; tensile stress at break 179 MPa; strain at break 3.0 %; HDT 328°C at 1.8 MPa; mold 180–200°C. |
| 450CA30 | 30 % carbon fiber, black | 675 Pa·s | 1.40 g/cm³ | For stiffness, wear resistance and low friction in static or moving parts. Tensile modulus 28,000 MPa; tensile stress at break 265 MPa; strain at break 1.7 %; HDT 336°C at 1.8 MPa; mold 180–210°C. |
Melt viscosity by ISO 11443 at 400°C for every row. A filled grade is not a substitute for unfilled 450G (or the reverse) without a drawing change; shrinkage, stiffness and elongation all move.
Grades to ask about instead of PEEK 450G
The first two rows are unfilled PEEK from other producers with flow in the same range as 450G. The third is a different polymer that buyers sometimes look at. None is a drop-in replacement. Producers name viscosity differently: Victrex calls 450G standard flow, Syensqo calls KT-820 low flow, and Evonik calls L 4000 G high viscosity. Compare the numbers at the same test condition, not the names. If your part, drawing or customer approval names Victrex 450G, any change needs your approval and usually a trial.
| Grade | Producer | Melt flow | Density | Key property | How it compares |
|---|---|---|---|---|---|
| KetaSpire KT-820 NT | Syensqo (Solvay Specialty Polymers) | Melt viscosity 440 Pa·s (400°C, 1000 s-1, ASTM D3835); MFR 3.0 g/10 min (400°C, 2.16 kg, ASTM D1238) | Specific gravity 1.30 (ASTM D792) | Tensile stress at yield 96 MPa and modulus 3,830 MPa (ISO 527); Tg 150°C, peak melt 340°C (ASTM D3418); HDT 157°C at 1.8 MPa, annealed, 3.2 mm (ASTM D648); UL 94 V-0 at 1.6 mm, V-1 at 0.8 mm | Close on paper, but a stiffer melt. Syensqo calls KT-820 its low-flow grade, and its listed melt viscosity is higher than 450G’s (different test standards, so treat the gap as approximate). Pellets are lightly dusted with calcium stearate (0.01 %); a non-lubricated natural version is sold as KT-820 NL. The HDT was measured annealed by ASTM, so it does not compare directly with 450G’s unannealed ISO value. Mold temperature 175–205°C. Needs qualification before you switch. Quote this alternative › |
| VESTAKEEP L 4000 G | Evonik | MVR 12 cm³/10 min (380°C, 5 kg, ISO 1133) | 1.30 g/cm³ (ISO 1183) | Tensile stress at yield 94 MPa and modulus 3,600 MPa (ISO 527); HDT 155°C at 1.8 MPa (ISO 75); melting point 340°C; V-0 at 1.6 mm (IEC 60695-11-10, UL yellow card listed as available) | Similar flow on paper. It is measured at the same condition as 450G’s MFR of 8.5 g/10 min, but MVR is by volume and MFR is by mass, so the numbers are not one-to-one. Evonik calls this grade high viscosity, and it carries an external lubricant. Listed tensile modulus is lower than 450G’s. Evonik recommends a 370–380°C melt and a 160–200°C mold. Ask for the UL file and regulatory letters, and plan a trial. Quote this alternative › |
| Ultem 1000 | SABIC | MFR 9 g/10 min (337°C, 6.6 kg, ASTM D1238) | Specific gravity 1.27 (ASTM D792) | Tg 217°C; HDT 192°C at 1.8 MPa (ISO 75/Af); RTI 170°C (UL 746B); UL 94 V-0 at 0.75 mm | Different polymer. Amorphous PEI with a higher Tg and HDT at 1.8 MPa, but a lower RTI than 450G, and buyers usually choose PEEK for chemical resistance. It shrinks differently and molds at 135–180°C, so the part and tool usually change. See Ultem 1000 and PEEK vs. PEI. Quote this alternative › |
From each producer’s published data. Typical values; confirm on the current producer data sheet. Evonik’s VESTAKEEP 2000 G is sold as medium viscosity but lists MVR 70 cm³/10 min at 380°C / 5 kg, much closer to Victrex 150G’s flow than to 450G’s.
Typical uses for PEEK 450G
Victrex’s data sheet and product page describe 450G for:
- General-purpose injection molded parts and extruded shapes in standard flow
- Parts that need higher strength and stiffness together with high ductility
- Parts exposed to aggressive chemical environments
- Parts that must withstand steam sterilization
- Replacing metal and other polymers; Victrex says PEEK as a family is used in aerospace, automotive, energy, industrial, electronics and medical parts (confirm 450G for your exact use, especially medical)
For thin walls or long flow lengths Victrex points to lower-viscosity grades such as 150G or 90G; for wire coating, film and filament it lists 381G.
What to check before you switch
- Confirm the exact code. 450G, 450G MIC, 381G, 150G, 90G, 450GL30 and 450CA30 are separate Victrex grades with different flow, form or fill. Do not accept one for another without approval.
- Compare flow numbers, not names. Viscosity labels do not line up across producers, and test methods differ (ISO 11443 vs ASTM D3835 melt viscosity; MFR by mass vs MVR by volume).
- Check for lubricant. KetaSpire KT-820 is dusted with calcium stearate and VESTAKEEP L 4000 G carries an external lubricant. If your application limits additives, ask for a non-lubricated version (Syensqo lists KT-820 NL) and the producer’s letter.
- Hold mold temperature. Victrex asks for 170–200°C at the mold surface; cold spots leave amorphous, brown areas with lower properties. Victrex also advises keeping copper alloys out of contact with the melt and cleaning barrels, dryers and hoppers before running PEEK.
- Dry it. Victrex lists 150°C for 3 hours or 120°C for 5 hours to below 0.02 % moisture. See our resin drying guide.
- Ask for each document by grade and color: UL file (the 450G sheet lists RTI values but no UL 94 rating), food-contact or medical statements, and any customer-required certifications. Alternatives may not carry the same listings.
- PEI is not a PEEK substitute without redesign, and the reverse. See PEEK vs. PEI and PEEK alternatives.
- Run a trial lot and check shrinkage (450G lists 0.90 % flow, 1.3 % across flow), crystallinity, cycle time and appearance before you switch production.
Buying PEEK 450G: 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. Material already in a partner warehouse usually moves sooner than a grade that has to come from the producer; your quote says which applies.
- Price. We do not publish prices because they move with feedstock, freight and order size. What moves your price most: lot size, color, ship-to region, and whether you need Victrex 450G itself or can accept 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 regulatory letter 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.
- If PEEK 450G itself is not available. Some branded grades are sold only through the producer’s own channels or go on allocation. If we cannot source it, we tell you, then quote a matched alternative with a side-by-side comparison.
Send the grade code, your annual volume and ship-to location. A polymer chemist checks it before we quote; we have been in the resin business for 30+ years. For several grades at once, use the resin RFQ template. See also the PEEK buying guide and PEEK typical properties.
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 sheets as of November 2026.
Sources
- Victrex PEEK 450G data sheet, March 2026 (PDF)
- Victrex 450G product page (MFR, 150G comparison, crystallinity)
- Victrex 450G MIC data sheet (PDF)
- Victrex PEEK 90G data sheet (PDF)
- Victrex PEEK 381G data sheet (PDF)
- Victrex PEEK 450GL30 data sheet (PDF)
- Victrex PEEK 450CA30 data sheet (PDF)
- Victrex: five factors to consider when molding PEEK
- Syensqo KetaSpire PEEK brand page
- Syensqo KetaSpire KT-820 data sheet, revised May 2024 (PDF, distributor-hosted)
- Evonik VESTAKEEP L 4000 G product information (PDF)
- Evonik VESTAKEEP 2000 G product information (PDF)
- SABIC ULTEM 1000 global technical data sheet, June 2026 (PDF, distributor-hosted)
Common questions
What is PEEK 450G?
PEEK 450G is Victrex’s general-purpose, unfilled, semi-crystalline polyetheretherketone (PEEK) for injection molding and extrusion. Victrex describes it as a standard-flow (standard melt viscosity), medium molecular weight grade, supplied as natural/beige granules.
What is the melt viscosity or melt flow of PEEK 450G?
350 Pa·s at 400°C (ISO 11443) on the data sheet. Victrex’s product page also lists an MFR of 8.5 g/10 min at 380°C, 5 kg (ISO 1133). Typical values; confirm on the current producer data sheet.
What is the difference between PEEK 450G and 150G?
150G is Victrex’s higher-flow, lower molecular weight grade: 130 Pa·s and MFR 75 g/10 min, against 350 Pa·s and 8.5 g/10 min for 450G. Victrex says 150G suits thin walls and highly filled compounds, while 450G is tougher (notched Izod 8.0 vs 5.0 kJ/m² in Victrex’s comparison table).
What are the Tg, melting point and HDT of PEEK 450G?
Glass transition 143°C onset and 150°C midpoint (ISO 11357-2), melting point 343°C (ISO 11357-3), and HDT 152°C at 1.8 MPa, unannealed (ISO 75-2/Af). The sheet lists RTI 260°C electrical, 240°C mechanical without impact and 180°C with impact (UL 746B).
Is PEEK 450G food-contact compliant?
The 450G data sheet does not include a food-contact statement, and Victrex’s 450G product page points to separate food grades that may be more suitable. Ask Victrex for a regulatory statement for the exact grade and color before using it in contact with food.
What is equivalent to Victrex PEEK 450G?
Unfilled PEEK from other producers to ask about includes Syensqo KetaSpire KT-820 NT and Evonik VESTAKEEP L 4000 G. These are matched alternatives, not identical: flow, lubricant and listings differ. Compare the data sheets, run a trial, and get approval if your part names 450G.
Can ResinBridge supply PEEK 450G?
We quote PEEK 450G when our supply partners can source it. If they cannot, we say so up front and quote a matched alternative, named on the quote with its data sheet, so you can decide whether to trial it.
If your grade is not listed, tell us what you run. We source commodity, engineering and specialty resins.
Need PEEK 450G or an equivalent?
A polymer chemist reviews every request, then matches your grade or finds a matched alternative and prices it.
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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