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18-7 - CK Worldwide 18-7 Back Cap Insulator for 17/18/26 Series TIG Torches

Packaging: 1 of each
$6.32/ea $4.26/1 of each only $4.26/eaSave 33%

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OVERVIEW

Industrial Grade Back Cap Insulator for 3 Series Torches

The CK Worldwide 18-7 Back Cap Insulator is a critical component designed for the maintenance and repair of standard TIG welding torches. Specifically engineered for the 3 Series torch bodies, this insulator is fully compatible with industry-standard models including the WP-17, WP-18, and WP-26, as well as their equivalents from major manufacturers such as Weldcraft, Miller, Lincoln, WeldTec, and Profax. The insulator serves a dual purpose in the torch assembly: it provides necessary electrical isolation between the charged torch body and the back cap, and it creates a seal to prevent the escape of shielding gas.

Manufactured from high-durability, heat-resistant materials, the 18-7 insulator withstands the thermal cycling inherent in TIG welding operations. Failure of this component can lead to gas turbulence, loss of shielding coverage, and potential electrical hazards if the back cap becomes energized. This part is a direct replacement for the standard 18-7 nomenclature found in technical diagrams for air-cooled and water-cooled torches in the 150A to 350A range. It is compatible with standard rigid bodies, flex heads, and valve-equipped models within the specified series.

For industrial MRO applications, maintaining a stock of 18-7 insulators is recommended to minimize downtime. The component is easily installed by hand during routine consumable changes or back cap adjustments. It fits seamlessly with standard collet bodies and gas lens setups, ensuring that the torch geometry remains within specification for optimal arc control.

Technical Specifications

  • Industry Standard Part: 18-7
  • Compatibility: 17, 18, 26, 150, 210, 300, 510, FL3L, CKM350, CWHTL300
  • Function: Electrical insulation and gas sealing
  • Installation Location: Rear of torch head, under back cap
Additional Information
Brand:CK Worldwide
Item:Insulator
Packaging Description:1-per-ea
Compatible Series:3 Series, 17 Series, 18 Series, 26 Series
Part Type:Back Cap Insulator
Torch Compatibility:WP-17, WP-18, WP-26, CS300, CKM350

INCLUDED

  • 1x 18-7 Back Cap Insulator

APPLICATIONS

  • TIG Welding (GTAW)
  • Torch Maintenance and Repair
  • Fabrication Shops
  • Automotive Repair
  • Aerospace Welding
  • Pipe Welding

FAQ

The 18-7 insulator fits 3 Series TIG torches. This includes standard models like the WP-17, WP-18, and WP-26, as well as CS300, CK210, and other equivalent torches from brands like Weldcraft, Miller, and Lincoln.

It is installed at the rear of the torch head. It sits between the torch body and the back cap to provide a seal and electrical insulation.

Over time, heat cycles can cause the insulator to crack or warp. A damaged insulator can allow shielding gas to leak out the back of the torch and may cause electrical shorts.

Yes, the 18-7 insulator is compatible with both standard collet bodies and gas lens setups, as it sits behind the collet body assembly.

No, 9 and 20 series torches (2 Series) use a different insulator. The 18-7 is specifically for 17, 18, and 26 series torches (3 Series).

It is made from a high-temperature, non-conductive composite material designed to withstand the heat of TIG welding and provide electrical isolation.

Usually, stubby kits for 17/18/26 torches use a special 18CG cup gasket on the front, but they still utilize the standard 18-7 insulator on the back for the back cap, unless the kit converts the entire head geometry.

Inspect it for visible cracks, chips, or signs of melting. If you hear gas hissing from the back of the torch or experience poor gas coverage despite good flow at the nozzle, check the insulator.