Zytel ST Super toughened Nylon

2026-09-09

1. What Is Super Toughened Nylon?

General-purpose nylon (PA) is a high-performance engineering plastic characterized by high strength, high rigidity, wear resistance, and chemical resistance. As a result, it is widely used in the automotive, machinery, electrical and electronics, home appliance, and industrial parts sectors. However, in applications involving low temperatures, high humidity, or repeated impact, standard PA66 may not meet the required toughness specifications.

Zytel Super Toughened Nylon is a super-toughened grade of nylon resin specifically developed by DuPont’s Performance Materials division. Through modification and processing, this material effectively enhances the impact strength and fracture toughness of nylon, enabling it to withstand more severe mechanical impacts and dynamic loading conditions.

Among these, the Zytel ST series consists of ultra-tough nylon, primarily intended for engineering plastic parts that require high impact resistance; the Zytel MT series consists of standard toughened nylon, primarily intended for applications with lower impact resistance requirements.

2. Key Properties of Super Toughened Nylon

The difference between toughened nylon and standard PA66 is that, while maintaining the basic strength and heat resistance of the nylon material, it enhances the material’s resistance to sudden impact and crack propagation.

2.1 Exceptional Impact Resistance

The most notable characteristic of the Zytel ST series is its exceptional impact toughness.
Take Zytel ST801 PA 6.6 as an example: its Izod notched impact strength is 80 kJ/m², whereas that of the commonly used general-purpose PA resin, Zytel 101L, is only 5.5 kJ/m², demonstrating significantly superior impact resistance. This ultra-high-toughness PA resin makes ST801 PA66 better suited for thin-walled parts, sharp corners, snap-fit applications, and scenarios involving stress concentration.
Zytel ST801 Ultra toughened PA66 Zytel 101L general purpose grade PA66 Unit
Izod notched impact 23℃  80 5.5 kJ/㎡
Charpy notched impact 23℃  80 5.5 kJ/㎡

2.2 Excellent Low-Temperature Flexibility

General-purpose nylon exhibits a significant decrease in toughness at low temperatures, whereas ultra-toughened PA66 maintains good impact resistance over a wide temperature range.
The technical specifications for Zytel ST801 NC010 nylon indicate that it maintains an Izod notched impact strength of 20 kJ/m² even at extreme low temperatures of -30°C, whereas Zytel 101L achieves only 5.5 kJ/m². This demonstrates that this material is better suited for use in automotive applications, outdoor equipment, and mechanical components that must withstand significant temperature fluctuations.
Zytel ST801 Ultra toughened PA66 Zytel 101L general purpose grade PA66 Unit
Izod notched impact -30℃  20 5.5 kJ/㎡
Charpy notched impact -30℃  20 4.5 kJ/㎡

2.3 Balance Between Strength and Toughness

Although Zytel Ultra-Tough series nylon materials offer high flexibility, this does not mean they sacrifice a significant amount of strength.
Compared to Zytel ST801 NC010 natural PA 66, which has a tensile modulus of up to 2,000 MPa, a flexural modulus of 1,800 MPa, and a tensile strength at yield of 50 MPa, it remains a high-performance engineering plastic that achieves a good balance among strength, stiffness, and impact resistance.

3. Zytel Super tough nylon resin applications

Nylon Car Luggage Rack

3.1 Automotive Applications

Zytel ST super-tough nylon resin, with its outstanding impact resistance, has a wide range of applications in the automotive industry, such as roof racks that must withstand long-term temperature fluctuations outdoors, fasteners that must endure prolonged dynamic vibrations, and automotive door handle assemblies that must withstand repetitive motion.

Nylon Drone Propellers

3.2 Drone Applications

The use of glass-fiber, nylon, and carbon-fiber-reinforced composite materials in drone propellers is already a well-established technical approach.

Zytel ultra-tough nylon not only meets the high-strength requirements for drone propellers, but also withstands centrifugal forces generated by high-speed rotation, impacts during takeoff and landing, long-term cyclic fatigue, impacts in low-temperature environments, and periodic vibrations.

Nylon ski bindings

3.3 Outdoor Sports Apps

For outdoor sports equipment—particularly equipment used in skiing—the material’s low-temperature resistance is of critical importance, and Zytel ST801 PA66 is ideally suited to meet this requirement.

According to official technical guidance documents from DuPont, Zytel ST801 nylon is specifically designed for use in snowmobile hinges and equipment mounts. It maintains excellent mechanical properties even at temperatures below 0°C, making it the material of choice for snow sports.

4. Selecting Zytel Ultra-High-Toughness Nylon

Typical Properties1 of Zytel® Super Tough and Toughened Nylon Resins
Property Units  ST801AHS   DMX ST601AH  ST901L  ST811HS   MT409AHS   DMXMT609AH 
 Zytel 101 
 Test Method
Ultra tough nylon Tough nylon Standard
Izod impact, notched
Dry, as molded
  J/m (ft-lb/in)  No break No break No break No break 133 (2.5) 81 (1.5) 53 (1.0) D 256
Elongation at break
Dry, as molded
50% RH
 %
50
-
21
43
>100
>100
>100
>100
35
-
3
16
60
>100
 D 638
Flexural modulus
Dry, as molded
50% RH
 MPa (kpsi)
1900 (276)
-
2050 (297)
2129 (309)
2000 (290)
2100 (300)
524 (76)
297 (43)
2400 (348)
-
2623 (380)
2641 (383)
2830 (410)
1210 (175)
 D 790
Tensile strength
Dry, as molded
50% RH
 MPa (kpsi)
48.4 (7.0)
-
52.1 (7.6)
48 (7)
62 (9.0)
52 (7.5)
48 (7.0)
41 (5.9)
61.2 (8.9)
-
62.5 (9.1)
58.3 (8.5)
83 (12.0)
77 (11.2)
 D 638
Heat deflection temp.
@ 1.8 MPa (264 psi)
 °C (°F) 61 (142) 62 (144) 115 (239) 52 (126) 52 (126) 65 (149) 65 (149) D 648
Melting point °C (°F) 261 (502) 259 (498) - 216 (421) 262 (504) 259 (498) 262 (504) D 3418
1: Properties shown are for comparison and preliminary evaluation. For more detailed properties, ISO properties and latest test results, please visit polyhdpe.com on the Web

References

  1. Dupont, "DuPont Zytel ST Super tough nylon resin", DuPont, 09/09/2026
  2. Baiyou, "Zytel ST801 PA66 Technical data sheet (TDS)", Baiyou, 09/09/2026
  3. Baiyou, "Zytel 101L PA66 Technical data sheet (TDS)", Baiyou, 09/09/2026
  4. Dupont, "DuPont Engineering Design Electronic Magazine 2007/1", Dupont, 09/09/2026

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