AWS : A5.20 E71T-1C
SF1 is an all-positional, seamless flux cored wire with a high deposition rate, easy and clean to weld.
Suitable for welding mild steel and 490MPa high tensile strength steel for machinery, non-seismic structures, etc.
Superior Japanese quality.
Available in 1.2mm and 1.4mm diameter.
NSSW uses base steel made by parent company, Nippon Steel, from their best virgin ‘A’ grade green bar.
Very high, consistent quality of steel and flux.
During manufacture the wire is dried before sealing to remove the maximum amount of hydrogen, typically results in hydrogen content of H2-3.
Once sealed (seamless), these wires are double coated in copper. Virtually impervious to moisture so do not gain hydrogen during shipping and storage.
SF1 has among lowest hydrogen content of all wires and is stable at that level.
Japanese engineering also ensures perfectly round wires, compared to many wires on the market which are slightly oval.
Being perfectly round means they do not spiral in the gun during welding, slide through liner/gun beautifully so go through much less consumables. Brilliant conductivity at tip.
SF1 is Seismic Grade 2, so more often used for machinery manufacturing than structural welding.