Ultramid A3K: specs and equivalent grades
BASF easy-flowing, unreinforced polyamide 66 (nylon 66) for fast-cycling injection molding. Published data, grades from other producers to ask about, and how to request a quote from one gaylord.
Request a QuoteThe short answer
Ultramid A3K is BASF’s easy-flowing, unreinforced polyamide 66 (PA66) for fast injection molding, used for highly stressed technical parts such as bearings and gear wheels. Published melt volume rate is 120 cm³/10 min, measured at 275°C / 527°F, 5 kg, ISO 1133, viscosity number is 150 cm³/g (ISO 307), and density is 1.13 g/cm³ (ISO 1183), per BASF’s product information dated 09/2026. Tensile modulus is 3,000 MPa dry and 1,100 MPa conditioned (ISO 527). Grades from other producers to ask about include Zytel 101L and Vydyne 21SPC. They are not identical, so compare the data sheets and run a trial before switching.
Also written as: A3K, Ultramid A3 K, ULTRAMID® A3K. BASF also sells colored and special versions under longer codes. Quote the full code from your drawing or bag label; color and additive suffixes change the grade.
Buying Ultramid A3K: 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.
Ultramid A3K specs from the data sheet
Typical values for uncolored product at 23°C from BASF’s product information and processing data sheet for Ultramid A3K (both dated 09/2026). Dry / conditioned values are shown where BASF gives both. 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) | BASF | BASF product information, 09/2026 |
| Polymer | Polyamide 66 (nylon 66), unreinforced | BASF polymer abbreviation: PA66 |
| Process | Injection molding | |
| Melt flow | MVR 120 cm³/10 min | 275°C / 527°F, 5 kg, ISO 1133 |
| Viscosity number | 150 cm³/g | ISO 307, 1157, 1628 (0.5% in 96% sulfuric acid) |
| Density | 1.13 g/cm³ (1,130 kg/m³) | ISO 1183 |
| Tensile modulus, dry / conditioned | 3,000 / 1,100 MPa (435,000 / 160,000 psi) | ISO 527-1/-2 |
| Yield stress, dry / conditioned | 85 / 50 MPa (12,300 / 7,250 psi) | ISO 527-1/-2, 50 mm/min |
| Yield strain, dry / conditioned | 4.5 / 20 % | ISO 527-1/-2, 50 mm/min |
| Nominal strain at break, dry / conditioned | 30 / >50 % | ISO 527-1/-2, 50 mm/min |
| Flexural modulus, dry | 2,900 MPa (421,000 psi) | ISO 178 |
| Notched Charpy impact, dry / conditioned | 23°C: 5 / 20 kJ/m²; −30°C: 4 kJ/m² dry | ISO 179/1eA |
| Notched Izod impact, 23°C, dry / conditioned | 5.5 kJ/m² / no break | ISO 180/A |
| HDT at 1.8 MPa / 0.45 MPa | 75°C / 167°F; 220°C / 428°F | ISO 75-1/-2 |
| Melting temperature | 260°C / 500°F | ISO 11357-1/-3, DSC |
| Temperature index (tensile strength, 50% loss) | 101°C / 214°F at 20,000 h; 118°C / 244°F at 5,000 h | IEC 60216 |
| Max. service temperature, short cycle | 200°C / 392°F | BASF |
| Mold shrinkage, parallel / normal | 1.50 % / 1.80 % | ISO 294-4 |
| Moisture absorption: 23°C / 50% RH; saturation in water | 2.5–3.1 %; 8–9 % | Similar to ISO 62 |
| Flammability | Passes ISO 3795 / FMVSS 302 at 1 mm and up. No UL 94 rating on this sheet; ask BASF for the UL listing of the exact code (for example A3K R01) | BASF product information |
| Electrical | CTI 600 (test liquid A); volume resistivity 1E13 / 1E10 Ohm·m dry / conditioned | IEC 60112; IEC 62631-3-1 |
| Drying | 80°C / 176°F for 4 h in a dry-air dryer, to 0.03–0.06 % moisture | BASF processing data sheet |
| Melt temperature | 280–300°C (536–572°F); optimum 290°C / 554°F; max. residence time 10 min | BASF processing data sheet |
| Mold temperature | 60–80°C (140–176°F); optimum 60°C / 140°F | BASF processing data sheet |
| Packaging forms | Bags and octagonal bulk containers (IBC) with liner; road or rail silo by agreement | BASF product information |
| Food contact | BASF’s product information makes no food-contact statement. Ask for the producer’s regulatory letter for the exact grade and color. |
Source data sheets are listed at the bottom of this page. Confirm against the current sheet for your exact grade code and color.
Unreinforced PA66 such as A3K loses most of its stiffness as it absorbs moisture: BASF’s tensile modulus drops from 3,000 MPa dry to 1,100 MPa at 50% RH. Design to conditioned values for parts in service. BASF’s heat aging stabilized easy-flow PA66 is Ultramid A3W.
Grades to ask about instead of Ultramid A3K
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 Ultramid A3K, any change needs your approval and usually a trial.
| Grade | Producer | Melt flow | Density | Key property | How it compares |
|---|---|---|---|---|---|
| Zytel 101L NC010 | Celanese | Not published (VN 150 cm³/g, ISO 307) | 1.14 g/cm³ (ISO 1183) | Tensile modulus 3,100 / 1,400 MPa dry / conditioned (ISO 527-2); yield stress 82 / 55 MPa; HDT 70°C at 1.8 MPa; UL 94 V-2 at 0.71 mm | Close match. Unreinforced PA66 with mold release and the same viscosity number. Slightly stiffer when conditioned on its sheet. Celanese’s current grade record confirms density, viscosity number, modulus, yield stress and HDT; the UL 94 rating is from the 2018 DuPont-era sheet. Celanese has owned Zytel since November 2022. Quote this alternative › |
| Vydyne 21SPC | Ascend Performance Materials | Not published | 1.14 g/cm³ (ISO 1183) | Tensile modulus 2,800 / 1,800 MPa dry / conditioned (ISO 527-2); yield stress 86 / 56 MPa; HDT 70°C at 1.8 MPa; UL 94 V-2 at 0.4–3.0 mm | Close match. General-purpose lubricated PA66 for injection molding. Ascend lists FDA 21 CFR 177.1500, EU 10/2011 and NSF 51 among agency ratings and UL file E70062. No viscosity number is published, so flow at your shot size needs a trial. Quote this alternative › |
From each producer’s published data. Brand owners and grade names change; confirm on the current data sheet.
Typical uses for Ultramid A3K
From BASF’s product information for Ultramid A3K:
- Highly stressed technical parts
- Bearings
- Gear wheels
- Parts that benefit from fast processing (BASF describes A3K as easy flowing)
What to check before you switch
- Flow: A3K is BASF’s easy-flowing PA66 (MVR 120 cm³/10 min at 275°C / 5 kg). Zytel 101L and Vydyne 21SPC publish no MVR, so check fill and cycle time on the alternative.
- Heat aging: A3K is not described as heat stabilized. If the part sees continuous heat, ask about Ultramid A3W (BASF), Zytel 103HSL or a heat-stabilized Vydyne grade.
- Flame rating: the A3K product information shows no UL 94 rating; Zytel 101L and Vydyne 21SPC list V-2. If your drawing calls out UL 94, match it to the exact code’s Yellow Card.
- Food contact: Vydyne 21SPC lists FDA and EU food-contact ratings; ask BASF for a regulatory letter on the exact A3K code if you need one.
- Dry to 0.03–0.06 % moisture per BASF. See the resin drying guide.
- Compare values at the same conditioning (dry as molded vs 50% RH) and ISO method.
- Run a trial lot and check shrinkage, cycle time and appearance before you switch production.
Buying Ultramid A3K: 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 Ultramid A3K itself or can accept a matched alternative. See how resin is priced, nylon price per pound 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 Ultramid A3K 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
- BASF Ultramid A3K product information, 09/2026 (PDF)
- BASF Ultramid A3K processing data sheet, 09/2026 (PDF)
- Celanese Chemille grade record, Zytel 101L NC010 (checked Oct 31, 2026)
- Zytel 101L NC010 technical data sheet, UL Prospector copy, May 2018 (PDF; UL 94)
- Ascend Vydyne 21SPC data sheet, April 2026 (PDF)
Common questions
What is Ultramid A3K?
Ultramid A3K is BASF’s easy-flowing, unreinforced polyamide 66 for fast injection molding, used for highly stressed technical parts such as bearings and gear wheels.
What is the melt flow of Ultramid A3K?
MVR 120 cm³/10 min, measured at 275°C / 527°F, 5 kg, ISO 1133, per BASF’s product information (09/2026). The viscosity number is 150 cm³/g (ISO 307).
What is equivalent to Ultramid A3K?
Grades from other producers to ask about include Zytel 101L and Vydyne 21SPC. None is identical; compare data sheets and run a trial, and get approval if your part names Ultramid A3K.
Is Ultramid A3K food-contact compliant?
BASF’s product information makes no food-contact statement. Ask BASF for a regulatory letter for the exact grade and color before using it in a food-contact part.
Can ResinBridge supply Ultramid A3K?
We quote Ultramid A3K 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 Ultramid A3K 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 Ultramid A3K or a matched alternative
A polymer chemist checks the data sheet and tells you exactly what you would get before you order.
Request a QuoteNot sure which grade fits your part?
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