PVC Coated STTB Conduit Hubs

Calbond PVC coated STTB 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. STTB style hubs are ‘Through-Bulkhead’ fittings used to pass conduit runs through firewalls or bulkheads up to 1/8” thick.


  • 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

PVC Coated STTB Conduit Hubs

Item NumberTrade Size (in)ABCMax Wall ThicknessWeight Per 100 (lbs)
PV1200STTB41 1/42.943.255.880.25100
PV1500STTB51 1/23.193.506.380.25120
PV2500STTB72 1/24.224.758.440.25250
PV3500STTB93 1/24.385.508.760.25420
PA0500STTBA11/21.842.003.680.19Contact Factory
PA0700STTBA23/ Factory
PA1000STTBA312.662.505.320.25Contact Factory
PA1200STTBA41 1/42.943.255.880.25Contact Factory
PA1500STTBA51 1/23.193.506.380.25Contact Factory
PA2000STTBA623.754.257.500.25Contact Factory
PA2500STTBA72 1/24.224.758.440.25Contact Factory
PA3000STTBA834.315.258.620.25Contact Factory
PA3500STTBA93 1/24.385.508.760.25Contact Factory
PA4000STTBA1044.446.258.880.25Contact Factory