Styron 666D: specs and equivalent grades
AmSty (Americas Styrenics) medium heat, medium flow crystal polystyrene (GPPS) for medical and packaging parts. Published data, grades from other producers to ask about, and how to request a quote from one gaylord.
Request a QuoteThe short answer
Styron 666D is a crystal (general purpose) polystyrene made by AmSty (Americas Styrenics) for North America, with medium heat resistance and medium flow. AmSty lists medical and packaging/disposables uses. AmSty's data sheet states that STYRON is a registered trademark of Trinseo LLC. Published melt flow is 8.0 g/10 min, measured at 200°C / 392°F, 5 kg, ASTM D1238, and specific gravity is 1.04 (ASTM D792). Grades from another producer to ask about include TotalEnergies Polystyrene 525B, 535B and 524B. They are not identical, so compare the data sheets and run a trial before switching.
Also written as: STYRON 666D. Quote the full code from your drawing or bag label; color and additive suffixes change the grade.
Buying Styron 666D: 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.
Styron 666D specs from the data sheet
Typical values from AmSty's published 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) | Made by AmSty (Americas Styrenics). AmSty's data sheet states STYRON is a registered trademark of Trinseo LLC, so AmSty is the producer, not the trademark owner. | Data sheet (2026) |
| Polymer | Crystal (general purpose) polystyrene, GPPS | |
| Process | Injection molding; AmSty also gives extrusion settings | |
| Melt flow | 8.0 g/10 min | 200°C / 392°F, 5 kg, ASTM D1238 |
| Density | Specific gravity 1.04 (ASTM D792) | |
| Tensile strength | 43 MPa (6,300 psi) | ASTM D638 |
| Elongation | 3 % | ASTM D638 |
| Tensile modulus | 3,172 MPa (460,000 psi) | ASTM D638 |
| Flexural strength | 61 MPa (8,800 psi) | ASTM D790 |
| Flexural modulus | 490,000 psi as listed. The data sheet is internally inconsistent: it also lists 3,478 MPa, but 490,000 psi is about 3,380 MPa (and 3,478 MPa would be about 504,000 psi). Ask AmSty which figure is correct. | ASTM D790 |
| Notched Izod impact, 23°C / 73°F | 21 J/m (0.4 ft-lb/in) | ASTM D256 |
| HDT 1.8 MPa (264 psi) / 0.45 MPa (66 psi) | 82°C / 180°F; 89°C / 192°F | ASTM D648 |
| Vicat softening temperature | 99°C / 210°F | ASTM D1525 |
| Mold shrinkage | 0.004 to 0.007 in/in | ASTM D955 |
| Flammability | UL 94 HB (UL file E326906) | Data sheet |
| Additives | None stated | |
| Food contact | AmSty states that when used unmodified to make food contact articles it complies with FDA 21 CFR 177.1640, subject to good manufacturing practice and the limits in the regulation. The sheet also lists USP Class VI and AmSty's medical application policy. | |
| Injection molding barrel settings | Nozzle 415 to 470°F (213 to 243°C); zones 1 and 2: 425 to 480°F (218 to 249°C); zone 3: 390 to 415°F (199 to 213°C) | AmSty Styron 666D sheet (March 2026), Typical Processing Conditions |
| Injection back pressure | 25 to 175 psi (2 to 12 bar) | AmSty Styron 666D sheet |
| Mold temperature | 60 to 150°F (about 16 to 66°C, converted) mold surface; AmSty advises the highest temperature that still holds the target cycle | AmSty Styron 666D sheet (gives °F only) |
| Sheet extrusion barrel settings | Zone 1: 350 to 380°F (177 to 193°C), rising to zones 5 and 6: 400 to 430°F (204 to 221°C); melt pump, adapter, pipes and screen changer 380 to 450°F (193 to 232°C); die 390 to 450°F (199 to 232°C) | AmSty Styron 666D sheet |
| Sheet extrusion melt and head pressure | Melt 380 to 450°F (193 to 232°C); head pressure 1,500 to 3,000 psi (10 to 21 MPa); polish rolls 150 to 220°F (66 to 104°C) | AmSty Styron 666D sheet |
| Sheet extrusion notes | Die set at 110 to 150% of sheet thickness; first polish roll gap about 95% of finished thickness; keep sheet orientation at or below 30%; mixing head or static mixer with roughly 4:1 compression ratio when adding colorant | AmSty Styron 666D sheet |
| Drying | Not published on the data sheet | AmSty Styron 666D sheet |
| Light transmission and haze | Not published on the data sheet | AmSty Styron 666D sheet (March 2026) |
| Packaging forms | Not published on the data sheet | AmSty Styron 666D sheet and GPPS product page |
Source data sheets are listed at the bottom of this page. Confirm against the current sheet for your exact grade code and color.
AmSty gives no drying step for 666D; its sheet says a larger cushion should be used only if the material contains moisture, air or excess volatiles that show up as silver or black streaks in the part.
Grades to ask about instead of Styron 666D
These grades from other producers have similar published specs. None is a drop-in replacement: additive packages, flow at molding shear rates, color and approvals differ. If your part, drawing or customer approval names Styron 666D, any change needs your approval and usually a trial.
| Grade | Producer | Melt flow | Density | Key property | How it compares |
|---|---|---|---|---|---|
| TotalEnergies Polystyrene 525B | TotalEnergies (produced in the United States) | 9.0 g/10 min (200°C / 392°F, 5 kg, ASTM D1238) | 1.04 g/cm³ | Flexural modulus 450,000 psi (ASTM D790); Vicat 101°C / 213°F (ASTM D1525) | Close match. Crystal PS for injection molding and cap layer coextrusion (medical and laboratory parts, tumblers, jewel boxes, cutlery). MFR 9.0 vs 8.0 g/10 min. TotalEnergies states FDA 21 CFR 177.1640, UL 94 HB, USP Class II and USP Class VI. Quote this alternative › |
| TotalEnergies Polystyrene 535B | TotalEnergies (produced in the United States) | 4.0 g/10 min (200°C / 392°F, 5 kg, ASTM D1238) | 1.04 g/cm³ | Flexural modulus 450,000 psi (ASTM D790); Vicat 106°C / 222°F (ASTM D1525) | Partial match. High heat crystal PS for injection molding, extrusion and blow molding (electronics packaging, cutlery, office accessories, medical, appliance components). Half the MFR of 666D, with more heat resistance. TotalEnergies states FDA 21 CFR 177.1640, UL 94 HB and USP Class VI. Quote this alternative › |
| TotalEnergies Polystyrene 524B | TotalEnergies (produced in the United States) | 9.0 g/10 min (200°C / 392°F, 5 kg, ASTM D1238) | 1.04 g/cm³ | Flexural modulus 450,000 psi (ASTM D790); Vicat 101°C / 213°F (ASTM D1525) | Partial match. Same published properties as 525B, but formulated for high gloss coextrusion capping and as a blending crystal, with reduced die buildup. Its sheet lists only those extrusion uses, not injection molding. TotalEnergies states FDA 21 CFR 177.1640, UL 94 HB and USP Class VI. Quote this alternative › |
From each producer's published data. Brand owners and grade names change; confirm on the current data sheet.
No second producer added. INEOS Styrolution's site (ineos-styrolution.com) still has an expired TLS certificate and was not worked around; no other listed producer publishes a U.S. GPPS sheet that could be opened. Suggested page line: 'Need a second producer besides TotalEnergies? Ask us; we check imported GPPS too.'
Typical uses for Styron 666D
From AmSty's data sheet:
- Medical
- Packaging and disposables
What to check before you switch
- The 666D data sheet contradicts itself on flexural modulus: 490,000 psi and 3,478 MPa are not the same value (490,000 psi is about 3,380 MPa). Confirm the correct figure with AmSty if stiffness is critical.
- TotalEnergies reports annealed heat distortion (200°F for 525B), while AmSty's sheet does not state annealing. Compare Vicat instead: 210°F for 666D, 213°F for 525B and 222°F for 535B.
- Crystal PS is brittle (666D: 21 J/m notched Izod), and the TotalEnergies sheets do not list Izod. Check part toughness and drop performance on a trial.
- AmSty makes GPPS at Marietta and Hanging Rock, Ohio, Allyn's Point, Connecticut, and Torrance, California. Ask which plant supplies your lot if origin matters.
- To stay with AmSty but get more heat, its GPPS table lists STYRON 675 at 7.5 g/10 min with a Vicat of 223°F.
- All three alternatives on this page are TotalEnergies grades. Ask us if you need another producer.
- Compare melt flow, density and impact only at the same test condition and method (ASTM vs. ISO results differ).
- Ask for the producer's food-contact or regulatory letter for the exact grade if the part needs one.
- Run a trial lot and check shrinkage, cycle time and appearance before you switch production.
Buying Styron 666D: 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 Styron 666D 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 Styron 666D 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.
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 October 2026.
Sources
- AmSty STYRON 666D technical data sheet (PDF)
- amsty.com/products/polystyrene-gpps
- TotalEnergies Polystyrene 525B data sheet (PDF)
- TotalEnergies Polystyrene 535B data sheet (PDF)
- TotalEnergies Polystyrene 524B data sheet (PDF)
Common questions
What is Styron 666D?
Styron 666D is a crystal (general purpose) polystyrene made by AmSty (Americas Styrenics) for North America, with medium heat resistance and medium flow. AmSty lists medical and packaging/disposables uses. AmSty's data sheet states that STYRON is a registered trademark of Trinseo LLC.
What is the melt flow of Styron 666D?
8.0 g/10 min, measured at 200°C / 392°F, 5 kg, ASTM D1238, per the published data sheet.
What is equivalent to Styron 666D?
Grades from another producer to ask about include TotalEnergies Polystyrene 525B, 535B and 524B. None is identical; compare data sheets and run a trial, and get approval if your part names Styron 666D.
Is Styron 666D food-contact compliant?
AmSty states that when used unmodified to make food contact articles it complies with FDA 21 CFR 177.1640, subject to good manufacturing practice and the limits in the regulation. The sheet also lists USP Class VI and AmSty's medical application policy.
Can ResinBridge quote Styron 666D?
Yes. Send the grade name and volume. A polymer chemist checks it and we quote the grade 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 Styron 666D 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
Quote Styron 666D or a matched alternative
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