Böhler ER 70 S-2 Triple-Deoxidized Mild Steel TIG Rod

Triple-deoxidised ER70S-2 rod for single-pass TIG on contaminated mild steel

Böhler ER 70 S-2 is a GTAW rod classified AWS A5.18 / SFA-5.18 ER70S-2. It contains aluminium, titanium and zirconium, strong deoxidisers that work together with manganese and silicon, which is why such rods are called triple deoxidised. Böhler Welding points to the advantage when welding rimmed or semi-killed mild steels, or where the joint preparation is rusty or contaminated. The rod is primarily used for single-pass welding, and the data sheet says it can be used in sour gas applications.

Technical specifications

Parameter	Specification
AWS classification	A5.18 / SFA-5.18 ER70S-2
Typical analysis, wt %	C 0.05; Si 0.5; Mn 1.2; Ti, Al and Zr present
Base materials	S235JR-S355JR, S235J0-S355J0, S235J2-S355J2, S275N-S420N, P235GH-P355GH, P355N, L245NB-L415NB, ASTM A 106 Gr. A, B, C, A 516 Gr. 55-70, A 573 Gr. 58-70, API 5 L Gr. B to X60
All-weld metal, as welded (typical)	Yield 61 ksi (421 MPa); tensile 75 ksi (517 MPa); elongation 23 %
Impact energy, as welded	133 ft-lbs at 68 °F; 89 at -20 °F; 59 at -60 °F
Polarity / shielding gas	DC-; I1 (argon)
Rod sizes (length 39 in.)	1/16; 5/64; 3/32; 1/8 in.
Approvals	None listed

When to choose ER70S-2 or a sibling

For applications involving single and multipass GTAW and for low-temperature toughness down to -110 °F (about -79 °C), Böhler recommends its ER70S-3 rod Böhler EML 5 instead. The silicon-rich

EMK 6.

(ER70S-6) is the alternative for clean boiler and vessel plate where deposit wetting is the priority. Because the deoxidisers in ER70S-2 take up oxygen and scale in the weld pool, the rod is a practical choice for maintenance and repair work, but it is no substitute for proper joint cleaning on code work.

Related Böhler TIG rod	AWS / EN ISO class	Typical use
EMK 6	ER70S-6 / W 3Si1	Carbon steel boiler, vessel and structural joints
Union ER 80S-B2	ER80S-B2	1.25Cr-0.5Mo creep-resistant steel
Thermanit 309L	ER309L / W 23 12 L	Dissimilar joints and buffer layers

Handling and what to confirm

Store rods in the box in a dry place, keep the argon supply pure and the flow stable, and avoid touching the rod ends with oily gloves. Clean the joint of rust, paint and oil, because even a triple-deoxidised rod cannot make up for gross contamination. Confirm diameter, pack weight, certificate level and the base steel before ordering, and consider a rod marking check on receipt.

Documents and quotation

The Böhler Welding data sheet for ER 70 S-2 (GTAW, US edition) is attached. Browse the TIG Welding Wire category for more rods. For a quotation, send diameter, pack size, quantity and certificate requirements.