ER308L40 - ER308L 5/32" Stainless TIG Welding Rod - 10lb Tube

Technical Overview of ER308L 4.0mm TIG Rods

The CWT308L40 is a premium-grade ER308L stainless steel TIG welding rod featuring a substantial 4.0mm (approximately 5/32 inch) diameter. Manufactured to strict AWS A5.9 specifications, this filler metal is an austenitic stainless steel formulation designed primarily for welding base metals of similar composition, such as AISI 304, 304L, 308, and 308L. The 'L' designation indicates an extra-low carbon content (maximum 0.03%), which is critical for minimizing the risk of carbide precipitation during the welding process. This feature significantly enhances the weld's resistance to intergranular corrosion, making it suitable for applications where the finished product will be exposed to corrosive environments or where post-weld annealing is not feasible.

With a diameter of 4.0mm, this rod is specifically categorized for heavy-duty applications. It allows for higher current settings and greater deposition rates compared to standard 1/16" or 3/32" rods, making it ideal for filling large V-grooves, welding thick-walled pipe, or fabricating heavy plate structures. The rod typically operates best with Direct Current Electrode Negative (DCEN) polarity using 100% Argon shielding gas to ensure a stable arc and a clean, oxidation-free weld pool. The chemical composition includes chromium (19.5-22.0%) and nickel (9.0-11.0%), providing excellent toughness and ductility at cryogenic temperatures as well as good creep strength at elevated temperatures.

Packaged in a durable 10 lb tube, these 36-inch cut lengths are maintained in a straight and clean condition to ensure smooth feeding through the welder's hand. The surface finish is matte or bright, free from contaminants that could introduce porosity into the weld. Quality control measures ensure consistent diameter tolerance and alloy distribution, providing industrial users with predictable performance for critical code work in petrochemical, food processing, and power generation sectors.