SikaFast 321 S Fast Curing Methacrylate Structural Adhesive

Learn More About the SikaFast 321 S Adhesive

Fast-curing and flexible, the SikaFast 321 S methacrylate adhesive is a two-component adhesive with a 10:1 mix ratio that comes in a 490 mL (16.5 fl. oz) cartridge. 

With an open time of 5 minutes, the SikaFast 321 S adhesive allows for quick fixturing in high-throughput applications. This high-performance adhesive also utilizes integrated spacer shims to ensure a uniform bond thickness of 0.024 to 0.033 inches. This combination makes it ideal for applications where consistency and speed are critical.

SikaFast 321 S glue provides strong adhesion across a range of substrates including metals and reinforced polymers. As such, it is a reliable alternative to mechanical fasteners like rivets or screws. Its rapid strength development increases production efficiency, while its high flexibility and elongation ensure a durable bond in applications with movement or vibration.

Key Features

• Rapid Curing: Strength develops within minutes, perfect for high-throughput applications
  
• Spacer Shims: Ensures consistent bond thickness of 0.027 to 0.033 inches
  
• Excellent Adhesion: Bonds effectively to metals, polymers, and composites with minimal surface prep
  
• High Flexibility: Maintains elasticity and performance, even at low temperatures
  
• Mix Ratio 10:1: Precise ratio for consistent application through static mixers
  
• 490 mL Cartridge: Ideal for large-scale bonding with easy dispensing

SikaFast 321 S Adhesive Specifications

• Series: SikaFast 321 S
  
• Type: Acrylic Structural Adhesive
  
• Chemistry: Methyl Methacrylate
  
• Application: Bonding
  
• Substrates: A Variety of Substrates Including Aluminum, Stainless or Galvanized Steel and Fiber Reinforced Polymers
  
• Color (Mixed): Straw
  
• Cure Mechanism: Radical Polymerization
  
• Cartridge Size: 490 mL (16.5 fl. oz)
  
• Density (Mixed): 8.3 lb/gal (0.99 kg/l)
  
• Mix Ratio: 10:1
  
• Consistency: Thixotropic Paste
  
• Application Temperature: 50°F to 95°F (10°C to 35°C)
  
• Open Time: 5 Minutes
  
• Peak Exotherm Time / Temperature: 10 Minutes / 195°F (90°C)
  
• Shore D Hardness: 65
  
• Tensile Strength: 1,300 psi (9 MPa)
  
• Elongation at Break: 80%
  
• E-Modulus: 14,500 psi (100 MPa)
  
• Tensile Lap-Shear Strength: 1,500 psi (10.5 MPa)
  
• Service Temperature: -22°F to 176°F (-30°C to 80°C)
  
• Shelf Life: 9 Months
  
• Storage Temperature: Below 72°F (22°C) - Protect from Direct Sun Light
  

Applications

With its great strength and flexibility, the SikaFast 321 S methacrylate adhesive is ideal for fast bonding and securing concealed joints. It replaces or complements mechanical fasteners like rivets or screws and bonds well to metals and reinforced polymers. It is a great choice for high-strength applications in automotive, industrial, and construction settings.