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High-flux bolt heaters

CETAL high-flux bolt heaters reduce the nut tightening and untightening time by heating while improving the safety of operators and heated material

Thanks to boron nitrid technology, you can drastically reduce your cycle time!

Main uses: tightening / untightening of drilled bolts through thermal expansion, maintenance of turbine engines, pressure equipments, for drop-forge installations, etc.

Main industrial sectors: Shipyards, thermal power stations, metallurgy

Reliability and robustness are key drivers for our engineers.

Product overview

  • Power up to 10kW (higher on request)
  • Watt density up to 40 W/cm² (To be checked)
  • Voltage max. 690 V


  • Very short heating time
  • Heating to approx. 350 °C (depending on the bolt material)
  • Easy handling
    • One operator per machine
    • One power outlet per bolt heater
  • Significantly reduces the assembling/deassembling time of large forged and cast-iron parts
  • Capacity to heat only the central part of the bolt
  • Long lifetime: 10 000 cycles
  • Workstation safety through low voltage < 50 V

Operating conditions

  • Normal (non-ATEX)
  • Hazardous areas (ATEX/IECEx) and NEC 505


  • Steel / Stainess steel bolts

Technical description

High performance through boron nitrid insulation

The use of boron nitrid as insulation allows to concentrate a lot of energy in a small space. The power is transmitted by radiation.

With this technology, high temperatures can be obtained in a short time, thus reducing to a few minutes the nut tightening/untightening time.


The bolt heaters are designed according to specifications using standard tube diameters.

Lenght and power are defined according to the bolt to be heated (size, Ø of drilling, mounting tolerance).

The bolt heaters can be supplied with 24 V (BT plug), 110 V, 230 V or other voltage.

The heating part of the bolt heaters is indicated through small machined grooves. To avoid incorrect installation, a positioning ring helps identifying the active zone.

CETAL expertise

After customer specification analysis, our engineers will drive you to the best solution for your process.


Tube material

  • Inox AISI 316L (1.4404)
  • Others on request

Tube / bolt diameters (mm)


Ø bolt heater

Ø H11 bolt





















Other diameters on request

Connection / Connection box

  •  24 V or 48 V plug
    • Female aluminum plug
    • Male plug, plastic, with cable
    • Thermal grease

  • Box filled with resin, 230-400 V

    • With HO7RNF or silicone cable
    • Thermal grease

  • Box with handle, 230-400 V

    • With or without LED
    • With HO7RNF or silicone cable
    • Thermal grease
  • Other connection boxes on request

(e. g, RATEAU connection box), can be supplied with simple threaded rods

  • Temperature sensors (thermostat, limiter, thermocouple or PT100) in the medium (process control) or on theheating element (safety control), on the flange or in the connecting box.
  • Voltage: VAC or VCC
  • Cabling according to main voltage VAC/VCC 1PH + N or 3PH
  • Power: < 10 000 W (higher on request)
  • Standard documentation
    • EU Certificate of Compliance
    • Instruction manual
  • On-request documentation
    • Certificate of conformity to the order
    • Supplied according to directives and standard
    • Material certificate 3.1 according to NF EN 10204
  • According to standard to comply with

  • Detachable cable (except for box filled with resin)
  • Other connection boxes on request
  • Power control panels
    • Power 5, 10, 15, 20 KVA
    • 24 V / 48 V, primary 230 V or 400 V
    • 110 V / 230 V on request