Böhler EMK 6 ER70S-6 Carbon Steel TIG Welding Rod

High-silicon TIG rod for boiler, vessel and structural joints

Böhler EMK 6 is a GTAW rod classified AWS A5.18 ER70S-6 (EN ISO 636-A W 3Si1) with a high silicon content. Böhler Welding describes it as suited for joints in boiler and vessel fabrication as well as structural steel engineering, and states that it can be used in sour gas applications (HIC test to NACE TM-02-84), with SSC test results available on request. It is the usual carbon-steel TIG rod for root and hot passes on pipe and for thin sections where a clean, tough deposit under argon is needed.

Technical specifications

Parameter	Specification
AWS classification	A5.18 / SFA-5.18 ER70S-6
EN ISO classification / rod marking	EN ISO 636-A W 3Si1
Typical analysis, wt %	C 0.08; Si 0.9; Mn 1.45
Base materials	Steels with yield strength below 420 MPa (60 ksi), including S235JR-S355JR, P235GH-P355GH, L245NB-L415NB, ASTM A 106 Gr. A, B, C, A 516 Gr. 55-70 and API 5 L Gr. B to X60
All-weld metal, as welded (typical, minimum)	Yield 65 ksi (448 MPa), min 61; tensile 81 ksi (558 MPa), min 73-93; elongation 28 %, min 20
Impact energy, as welded	133 ft-lbs at 68 °F; 59 at -40 °F; min 35 at -60 °F
Stress relieved (1110 °F, 2 h)	Yield 58 ksi (400 MPa); tensile 74 ksi (510 MPa); elongation 28 %; 133 ft-lbs at 68 °F; 81 at -40 °F
Polarity / shielding gas	DC-; I1 (100 % argon)
Rod sizes (length 39 in.)	1/16; 3/32; 1/8 in.
Approvals	TÜV (09717), CE

Selection, siblings and welding notes

The data sheet figures were measured with 100 % argon shielding on a rod of this type, so use the same gas when matching the numbers. For single-pass work on rusty or semi-killed steel, the triple-deoxidised

ER 70 S-2.

is the alternative, and for stainless joints see

Thermanit JE-308L.

. Take preheat and interpass temperature from the qualified WPS and the base material thickness.

Related Böhler TIG rod	AWS / EN ISO class	Typical use
ER 70 S-2	ER70S-2	Single-pass work on rusty or rimmed mild steel
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

Keep rods in the original box until use, keep them dry and free of oil and handling dirt, and read the rod marking before welding so that carbon and alloy rods are not mixed. Confirm diameter, length, pack weight and certificate level when ordering, and the sour-service test report if NACE conditions apply.

Documents and quotation

The Böhler Welding data sheet for EMK 6 (GTAW, US edition) is attached. Related items are in the TIG Welding Wire category. For a quotation, send diameter, pack size, quantity and certificate requirements.