Overview

Super glue is the common name for a family of fast-setting adhesives based on cyanoacrylate chemistry. Sold under many trade names, these adhesives are prized for forming bonds quickly and holding many common materials such as metal, ceramic, many plastics, wood and rubber. Because they cure very rapidly at room temperature they are often called instant glues.

Chemistry and key properties

Cyanoacrylates polymerize rapidly in the presence of trace moisture and certain anions on surfaces, creating long chains that produce a hard, rigid bond. The reaction is typically exothermic and proceeds almost immediately on contact with damp substrates. Different formulations vary in viscosity and monomer type (methyl, ethyl, butyl and other alkyl cyanoacrylates), which affects open time, flexibility and suitability for porous or nonporous surfaces. For a concise technical summary see related reference.

Common physical characteristics include high tensile strength but relatively poor performance under sustained shear or when gaps separate bonded parts. Special lower–brittleness or gap-filling grades exist, and additives can improve impact resistance or adhesion to difficult plastics. Packaging is typically small tubes or ampoules to limit exposure to humidity; see typical packaging notes here.

Uses and examples

Super glue is used in household repairs, hobby and model-making, electronics assembly, woodworking touch-ups and many industrial applications where a rapid bond is needed. Medical and veterinary formulations have been adapted to close small wounds and surgical incisions; these are produced to standards that reduce irritation and toxicity — more on medical grade products here. For a comparison of bond strength and applications consult testing summaries.

Safety, handling and removal

Although generally low in systemic toxicity, cyanoacrylates can irritate skin, eyes and respiratory mucous membranes. Bonding skin accidentally is common; removal strategies include soaking in warm soapy water, gentle mechanical separation after softening, and acetone-based solvents when appropriate. Because cured glue can be brittle, avoid forceful prying that may cause injury. Guidance on mechanical limitations (such as shear weakness) is available in technical notes.

History and notable distinctions

Discovered and commercialized in the mid-20th century, cyanoacrylates transformed many repair and assembly tasks by offering near-instant adhesion. The term "super glue" has become generic in everyday use, though proprietary names remain in commerce. Distinct adhesive classes (epoxies, polyurethanes, silicones) are chosen instead of cyanoacrylates when flexibility, gap-filling or prolonged cure control are required.

  • Advantages: rapid cure, strong bond on many substrates, easy to store in small amounts.
  • Limitations: brittle cured material, poor long-term resistance to some solvents and shear loads, sensitivity to moisture during storage.
  • Safety note: avoid contact with eyes and do not attempt to remove tense eyelid bonds without medical help.