HTM® 556 is a controlled flow, toughened bismaleimide (BMI) matrix system offering improved handling characteristics and after an appropriate post-cure, thermal cycling capability up to 250°C (482°F).
HTM® 556 has been developed for structural applications where continuous service temperatures exceed 200°C (392°F).

Features and Benefits
• 30 days out life at 21°C (70°F) ;
• 12 months storage at -18°C (0°F) ;
• Controlled flow ;
• Excellent tack and drape with improved ambient temperature tack stability ;
• No hot debulks required ;
• Free-standing post-cure ;
• Maximum DMA E’ onset Tg of 270°C (518°F) after post-cure to 240°C (464°F) ;
• Upper service temperature 250°C (482°F).


  • Global Business Unit
    Composite Materials
  • Brand


Segments Applications
Airframe Primary structural materials

Chemical categories

Chemical category Chemical family Chemical product
Composites Thermoset BMI

Region of commercial availability

  • North America

Download documentation for HTM 556