Bolt Heaters

Bolt heater stylesBolt Heaters are used to preheat large, hollow holding bolts or studs where a high concentration of heat is critical for bolt expansion in a short period of time. As an insertion type unit, the bolt heater is widely used in the manufacture and servicing of heavy duty steam or other pressure equipment. It is also used to heat die blocks and large platens and to expand adjusting bolts on mechanical or hydraulic presses.

Bolt Heaters are used as an aid to tighten large bolts in heavy machinery and equipment. Heaters are sized for easy insertion into a drilled hole in the bolt. The rapid heating of the bolt expands it allowing further tightening of the nut. The heater is then de-energized and removed. As the bolt cools its contraction back to original size provides a tight fit. Our bolt heaters are constructed with an efficient and high quality heating element.

Features:

  • Swaged tubular heater construction
  • 4″ octagon electrical enclosure with knock outs for easy wiring
  • Insulated handle
  • Special watt densities, wattages, and lengths, and diameters
  • Flexible designs available
  • Fast response time
  • Power leads and plug assemblies

Cartridge heater details

  1. High Temperature Lead Wires for temperatures up to 550° C.
  2. High Impact Ceramic Cap retards contamination and is suitable for high vibration applications. Deep holes in cap prevent fraying of leads when bent.
  3. Nickel-Chromium Resistance Wire for maximum heater life, evenly wound for even heat distribution.
  4. High Purity Magnesium Oxide fill selected for maximum dielectric strength and thermal conductivity, highly compacted for maximum heat transfer.
  5. 304 Stainless Steel Sheath for oxidation resistance in a wide variety of environments. 316 Stainless Steel and Incoloy® are also available. Please consult the Sheath Suitability Chart to determine which material is best for your application.
  6. TIG Welded End Disc to prevent contamination and moisture absorption.

Standard Specifications

Nominal
Diameter
Minimum
Diameter
Maximum
Diameter
Std. Lead
Wire Gage
Max Amps
w/ Std. Gage
Max Lead
Wire Gage
Max
Amps
Max
Volts
1/8″ .119 .124 24 3.6 24 3.6 240
1/4″ .244 .249 24 6 22 9 300
6.5 mm .250 .255 24 6 22 9 300
5/16″ .306 .311 24 6 22 9 300
8 mm .309 .314 24 6 22 9 300
3/8″ .369 .374 22 9 18 15 480
10 mm .388 .393 22 9 18 15 480
12 mm .466 .471 22 9 18 15 480
12.5 mm .486 .491 22 9 18 15 480
1/2″ .494 .499 22 9 18 15 480
13 mm .506 .511 22 9 18 15 480
17/32″ .525 .530 22 9 18 15 480
14 mm .545 .550 18 15 14 26 480
5/8″ .619 .624 18 15 14 26 480
16 mm .624 .629 18 15 14 26 480
17 mm .663 .668 18 15 14 26 480
11/16″ .682 .687 18 15 14 26 480
19 mm .742 .747 18 15 14 26 480
3/4″ .744 .749 18 15 14 26 480
25 mm .978 .983 18 15 14 26 480
1″ .994 .999 18 15 14 26 480
  • Length tolerance is +/- 3% or +/- 3/32, whichever is greater.
  • Camber tolerance is .025″ per foot of length. Slight camber is normally not a problem since the heater will flex enough to enter a clean hole.
  • Wattage tolerance is +5%, -10%
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