ThePipingMart Blog Welding Electrodes AWS Class ER308LSi MIG & TIG Welding Wire – Composition, Properties, and Uses

AWS Class ER308LSi MIG & TIG Welding Wire – Composition, Properties, and Uses

AWS Class ER308LSi MIG & TIG

AWS Class ER308LSi is one of the most common stainless steel alloys for welding applications. It’s ideal for welding various materials, including stainless and low-carbon steel.

This alloy has an ISO classification of AISI 308LSi but is also called AWS A5.9 Class ER308LSi. If you are wondering what makes it different from other alloys in the same category, keep reading because we will dive deeper into everything you need to know about AWS Class ER308LSi MIG & TIG.

What is AWS Class ER308LSi Welding Wire MIG & TIG?

AWS Class ER308LSi MIG & TIG welding wire are types of stainless steel welding processes professional welders use. The ER308LSi is an alloy of iron and various other elements, including chromium, nickel and silicon. These alloys provide excellent corrosion resistance and ductility when used in MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas) welding processes. During the MIG process, a consumable wire is fed through a hand-held gun to create the weld joint, while an inert gas is supplied to protect the molten metal from contaminants that can weaken it during cooling. A non-consumable tungsten electrode heats the metal workpiece to add filler material to create the desired weld joint shape for TIG welding. MIG and TIG welds produce strong joints with high fatigue strength, but proper technique must be applied for the best results.

ER308LSi MIG & TIG Coated Wire Composition

The AWS Class ER308LSi is an austenitic stainless steel welding alloy. It contains 19% chromium, 10% nickel and 2% molybdenum. Silicon gives it good arc stability, flow characteristics, and weld puddle fluidity. It is designed to be used with argon-based shielding gases as it can easily crack with carbon dioxide or nitrogen mixtures.

C Cr Ni Mo Mn Si P S Cu
0.03 19.5-22.0 9.0-11.0 0.75 1.0-2.5 0.65-1.00 0.03 0.03 0.75

ER308LSi MIG & TIG Welding Wire Physical Properties

AWS Class ER308LSi MIG & TIG has a 7.96 g/cm³ density, a thermal expansion coefficient of 17.2μm/m-°C, and a specific heat of 460 J/kg-°C. This alloy is paramagnetic, which means it displays a weak magnetic attraction.

ER308LSi MIG & TIG Coated Wire Mechanical Properties

AWS Class ER308LSi MIG & TIG welding electrode has a tensile strength range of 620-780 MPa and a yield strength of 370 MPa. It has a high elongation of 35%, which means it can stretch a considerable amount before breaking.

Tensile Strength (psi) 86,000 psi (593 MPa)
Yield Strength (psi) 57,000 psi (393 MPa)
Elongation (%) 42%

ER308LSi MIG & TIG Welding Wire Trade Names

ER308LSi S30888 Alloy 308LSi EXATON 19.9.LSI BOHLER THERMANIT JE – 308L UTP A68 LC

ER308LSi MIG & TIG Coated Wire Parameters

Diameter Process Volt Amps
in (mm)
.023 (0.6) GMAW 14-19 30-85
.030 (0.8) GMAW 15-20 45-125
.035 (0.9) GMAW 16-22 60-150
.045 (1.14) GMAW 17-22 90-210
1/16” (1.6) GTAW 12 80-150
3/32” (2.4) GTAW 12 150-250
1/8” (3.2) GTAW 12 200-375

ER308LSi MIG & TIG Welding Wire Uses

AWS Class ER308LSi filler wire is commonly used in the food, beverage, pharmaceutical, and chemical industries. It welds stainless steel components such as pipes, tanks, and machine parts. It is also used for welding low-carbon and stainless steel parts that require maximum resistance to corrosion and heat.

ER308LSi MIG & TIG Coated Wire Heat Treatment

AWS Class ER308LSi MIG & TIG is not heat-treatable. However, it can be subjected to post-weld heat treatments, such as annealing, to relieve residual stress.

ER308LSi MIG & TIG Welding Wire Corrosion Resistant

AWS Class ER308LSi MIG & TIG filler metal has excellent corrosion resistance, making it ideal for welding applications that resist corrosion due to various environmental factors. This alloy is resistant to corrosion in highly oxidizing environments and has good resistance to stress corrosion cracking.


In conclusion, AWS Class ER308LSi MIG & TIG is a flexible and reliable alloy for welding various materials. As with any welding application, it’s crucial to understand the chemical composition, physical and mechanical properties, and the intended use of the alloy. Consult a qualified welding professional if you need assistance selecting the right welding material.

Related Post