B3 Phenolic Paper Laminate

B3 Phenolic Paper Laminate

B3 phenolic paper laminate is similar to B1 in its composition but offers superior performance when submersed in oil. The layered paper is bonded with a synthetic, plasticised resin. This creates a rigid, plastic like material suitable for medium voltage, electrically insulating applications. This material is supplied as a direct alternative to genuine TUFNOL® 1P/21, which has since been discontinued.

Due to its rigid nature, B3 laminate can be processed using the same techniques as plastic sheet material. Our extensive in-house capabilities allow us to saw, drill, mill and route the material into complex components and parts as required. See our machining service page for additional information.

B3 is manufactured to BS EN 60893 Standard: 3-4-PFCP203.


B3 was originally developed for electrical insulation in medium voltage, oil submersed applications. Typical components include terminal boards, tag strips, mounting plates, coil formers, busbar supports and general mechanical components.

Key Features

  • Temperature: Up to +105°C continuous (+120°C intermittent).
  • Better oil absorption than grade B1.
  • Low water absorption; between grade B1 and B4.
  • Good mechanical and electrical properties.


  • BS EN 60893 Standard: 3-4-PFCP203.
  • BS 2572 Standard: P2 (since superseded by BS EN 60893).
  • Closest Nema Standard equivalent: Nema XX.
  • Closest MIL Specification: MIL-I-24768/11.


Body Colour: Brown.
Cover Colour: Sepia Brown.
Sheet Finish: Satin/Glossy.
Sheet Size (mm): 1220 x 1220.
Sheet Thickness (mm): 0.8 up to 75.
Technical Specification: