LongTeng ER70S-3 TIG Welding Rod for Carbon Steel

LongTeng ER70S-3 TIG Welding Rod for Mild Steel Fabrication

LongTeng ER70S-3 TIG is a carbon steel filler wire for gas tungsten arc welding, listed by Jiangsu Longteng Special Steel Group under AWS A5.18 ER70S-3. TIG welding is the process of choice when weld appearance, precision and low spatter matter more than deposition speed, and ER70S-3 is the traditional general purpose filler for it on mild steel. The manufacturer catalogue describes the grade as suitable for general steel fabrication, including automotive structures, small trailers, roof joists, railcar repair, exercise equipment, furniture and other mild steels.

Seven Star LLC supplies LongTeng welding consumables from Muscat to workshops, contractors and maintenance teams in Oman and the GCC. This page is dedicated to LongTeng ER70S-3 TIG, which is separate from the MIG wire carrying the same AWS class, and it sets out the values printed in the catalogue together with the notes an engineer needs when specifying filler metal. Every figure is a typical value listed by the manufacturer and not a Seven Star LLC guarantee; the batch certificate remains the reference document.

What the ER70S-3 Class Means

In AWS A5.18, the ER prefix identifies a wire that can be used as an electrode or as a rod, the 70 refers to a minimum tensile strength of 70 ksi in the weld metal, the S marks a solid wire and the 3 identifies a specific chemistry. As general class information, the 3 chemistry carries moderate levels of silicon and manganese, enough to deoxidise the weld pool in a clean argon shield but with less deoxidiser than the S-6 class. That makes the wire a good match for clean, ground or lightly scaled mild steel, which is how most TIG work is prepared.

The catalogue figures for LongTeng ER70S-3 TIG show manganese at 1.31 percent and silicon at 0.58 percent, with phosphorus at 0.012 and sulphur at 0.008 percent. Nickel, chromium, molybdenum and vanadium appear only as residuals, at 0.018, 0.020, 0.020 and 0.011 percent, and copper is 0.11 percent. The catalogue carbon entry for this grade is printed as 0.008 percent, which is below what the ER70S-3 class normally contains, so we treat it as a probable typographical error and do not repeat it; use the test certificate for the carbon level.

Mechanical Results in the Datasheet

The LongTeng ER70S-3 TIG catalogue lists typical tensile strength of 550 MPa, yield strength of 450 MPa and elongation of 26 percent. Impact energy is printed as 116, 108 and 110 J at minus 20 degrees Celsius. These numbers describe an all-weld-metal test of LongTeng ER70S-3 TIG under the manufacturer’s conditions, and they indicate comfortable margin over the class minimum together with good low-temperature toughness for a mild steel filler. For code work, take acceptance values from the certificate supplied with the delivered batch of LongTeng ER70S-3 TIG wire.

Gas and Current Reference

TIG shielding for LongTeng ER70S-3 TIG is pure argon. The catalogue pairs a gas flow of 7 to 12 L/min with a current of 100 to 200 A, and a gas flow of 12 to 15 L/min with 200 to 300 A. Wire diameters for the TIG range are not itemised on the catalogue page, so specify the rod diameter in your enquiry. As general practice, the rod diameter is chosen from the joint thickness and the current: thin sheet uses thin rod at low amperage, while heavy sections use larger rod with higher current and a larger gas cup. Electrode negative polarity with a ground tungsten is the normal TIG set-up for carbon steel.

Highlights of LongTeng ER70S-3 TIG

These points summarise what the printed catalogue supports for LongTeng ER70S-3 TIG.

• It is cited to AWS A5.18 ER70S-3, a long-established class for mild steel TIG and MIG filler wire.
• Typical weld metal strength is listed at 550 MPa tensile and 450 MPa yield.
• Elongation of 26 percent is listed, indicating a ductile deposit.
• Impact energy of 116, 108 and 110 J at minus 20 degrees Celsius is shown.
• Manganese and silicon deoxidisers are present at 1.31 and 0.58 percent.
• Phosphorus and sulphur are low, at 0.012 and 0.008 percent.
• Reference operation uses pure argon with currents from 100 to 300 A.

Typical Jobs and Regional Use

The manufacturer lists light structures and fabricated products for LongTeng ER70S-3 TIG, from vehicle frames and small trailers to railcar repair, roof joists, fitness equipment and furniture. In Oman and across the Gulf, the same kind of mild steel TIG work appears in workshop frames, brackets, guards, tank fittings, handrails, ducting supports and root passes in small bore carbon steel piping. Maintenance teams at industrial zones in Muscat, Sohar and Salalah use this class when they need a neat, clean bead on thin or medium material.

When a root pass must be sound, cleanliness is vital: remove oil, rust and mill scale from the joint and the rod, and keep the filler end out of draughts. Welding machines suitable for TIG work in our range include the ESAB Rebel EMP 285ic and the Lincoln Electric Power Wave S500, both multi-process units. To check the hardness of repaired components, a portable instrument such as the Phase II PHT-3500 portable hardness tester is a common choice.

Technical Specifications

The table lists the values printed for LongTeng ER70S-3 TIG in the manufacturer catalogue. Carbon is omitted because the printed value is not consistent with the class. The datasheet extract is attached to this page.

Handling and Quality Tips

Store LongTeng ER70S-3 TIG filler in its original packing, dry and clean, and keep it away from oil and grinding dust. Wipe each rod before use if it has been handled in a dirty environment, and discard the last short stub rather than welding with a contaminated end. Contamination on filler metal shows up as porosity and black deposits in the weld pool. Match the tungsten electrode, cup size and gas flow to the current, and check for gas leaks in hoses, because even a small air leak in an argon line can spoil a TIG weld.

How to Order

To request a quotation for LongTeng ER70S-3 TIG, send Seven Star LLC the rod diameter, quantity and delivery point you require in Oman or the GCC. Our Muscat team will confirm the available packing, share the datasheet extract and recommend that you ask for the batch test certificate, so that your quality file holds the verified mechanical and chemical values for the consignment.