EPIBOND 420

Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other

EPIBOND 420

Main features

  • Structural Applications Epoxy Bonding
  • Room-Temperature Adhesive Cure
  • Extremely Tough and Resilient

Product Description

Huntsman EPIBOND® 420 A/B Structural Epoxy Adhesive is a two-component, modified epoxy adhesive designed for structural bonding applications requiring high strength, toughness, and resilience. This room-temperature curing paste is suitable for bonding metals, honeycomb structures, and fiber-reinforced composites in demanding assemblies. The adhesive incorporates 5 mil (125 μm) spacer beads to help maintain a consistent bond line in high-stress joints. EPIBOND® 420 A/B offers a practical combination of room-temperature processing flexibility and accelerated heat-cure options, making it suitable for a range of aerospace, industrial, and composite bonding applications.

Key features

  • Structural epoxy formulation: Developed for high-strength bonding of metals, honeycomb materials, and fiber-reinforced composite substrates.
  • Controlled bond-line thickness: Contains 125 μm spacer beads to help maintain a uniform adhesive bond line in high-stress assemblies.
  • Flexible curing options: Supports room-temperature cure or accelerated thermal cure schedules to accommodate different manufacturing requirements.

Applications / Suitable for

  • Metal-to-metal structural bonding
  • Honeycomb panel assembly
  • Fiber-reinforced composite bonding
  • Aerospace structural assemblies
  • Industrial structural adhesive applications

Technical Specifications

General Properties
Color Color
Blue-green
Component System Component System
Two (Resin / Hardener)
Density (g) Density (g)
1.05 g/cm3

Additional Information

Technical properties

As-supplied / before-processing properties

Typical as-supplied properties for the EPIBOND® 420 A/B adhesive system.

Property Value Unit Method / condition
Mix ratio 100 : 40 wt. ratio 420 A Resin : 420 B Hardener
Density 1.05 g/cm³ ASTM D792, mixed system
Appearance Blue-green — Mixed adhesive system
Work life 70 minutes 77°F (25°C), ASTM D1338
Viscosity Semi-paste — 77°F (25°C), ASTM D2196
Shelf life 1 year Stored at +2°C to +40°C in sealed container
Technical properties

After-processing / final-state properties

Typical cured properties after one hour at 250°F (121°C). Values are typical data and not specifications.

Property Value Unit Method / condition
Lap shear strength 3500 (24.1) psi (MPa) Al-Al, ASTM D1002, 77°F (25°C)
Insert shear strength 1500 (10.3) psi (MPa) As cured, BMS 5-107
Insert shear strength retention 1400 (9.6) psi (MPa) After 30 days at 140°F (60°C), 95% RH, BMS 5-107

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