STTTB Conduit Hubs

Allied Tube & Conduit PVC coated STTTB conduit hubs are used to terminate conduit runs through the wall of a sheet metal electrical enclosure. They are available with or without grounding lug. STTTB style hubs are “Through-Bulkhead” fittings used to pass conduit runs through firewalls with unlimited wall thickness. (furnished without nipples)


  • Exterior PVC coating thickness is a minimum 0.040″
  • Interior Urethane coating thickness is a minimum 0.002″
  • STG and STTB available in 12 trade sizes from 1/2″ through 6″
  • Sealing sleeves on conduit side of hub
  • Molded PVC gasket seals flush with enclosure wall
  • Neoprene O-ring gasket provides additional seal
  • The length of the sleeve extension(s) shall be at least equivalent to the nominal conduit size for sizes 1/2″- 2″
  • For sizes 2-1/2″- 6″, the length of the sleeve extension(s) shall be at least 2″


  • UL 514B
  • NEC/CEC:
    • Class I, Division 2,
    • Class II, Division 1 & 2
    • Class III, Division 1 & 2
    • Class I, Zone 1, AEx e II
    • Class I, Zone 1, Ex e II
  • All Screw-tight Hubs are listed for NEMA type enclosures 2, 3, 3R, 4, 4x, 11 and 12
Item NumberTrade Size (in)ABCWeight Per 100 (lbs)
PV1200STTTB41 1/42.943.255.88200
PV1500STTTB51 1/23.193.506.38240
PA0500STTTBA11/21.842.003.68Contact Factory
PA0700STTTBA23/ Factory
PA1000STTTBA312.662.505.32Contact Factory
PA1200STTTBA41 1/42.943.255.88Contact Factory
PA1500STTTBA51 1/23.193.506.38Contact Factory
PA2000STTTBA623.754.257.50Contact Factory