Best Welds 900-98w18 O-ring Tig Torch Back Cap

Product Description

The BEST WELDS 900-98w18 is a replacement O-ring designed for use with TIG welding torches and back caps. O-rings in TIG torch assemblies create the gas-tight seal between the back cap and torch body, preventing argon or helium shielding gas from escaping at the rear of the torch. A failed or worn O-ring results in shielding gas loss, inconsistent arc starts, and potential weld contamination. This part is a direct replacement component intended for installation by welding equipment technicians or experienced welding professionals performing routine torch maintenance.

This O-ring is compatible with the 17, 18, and 26 series TIG torch bodies, as well as the 300M back cap and 57Y02 and 57Y04 back caps. These torch series are widely used in both light industrial and professional shop environments for GTAW (TIG) welding on steel, stainless steel, and aluminum. It is a consumable maintenance item typically replaced during torch inspections or when shielding gas leaks are detected at the back cap.

Key Features

• Seals the back cap-to-torch body interface to prevent shielding gas leakage
• Compatible with 17, 18, and 26 series TIG torch bodies
• Fits 300M, 57Y02, and 57Y04 back caps
• Routine consumable for preventive torch maintenance
• Direct OEM-style replacement fit

Compatibility

Compatible with 17, 18, and 26 series TIG torches, and fits 300M, 57Y02, and 57Y04 back caps as stated by the manufacturer.

Installation Notes

Installation is performed by welding equipment technicians during routine torch servicing or troubleshooting of shielding gas leaks. Before replacing the O-ring, turn off the shielding gas supply at the regulator and ensure the torch is disconnected from the power source. Inspect the back cap seating surface for scoring or debris before installing the new O-ring. Do not use petroleum-based lubricants on O-rings in gas-service applications unless specifically approved for that use.

Technical Specifications

• Part Type: O-Ring
• Application: TIG Torch Back Cap Seal

Standard Information

• Brand: BEST WELDS
• Manufacturer Part Number: 900-98w18