OK Flux 350 is an active bonded flux for making butt and fillet welds in carbon steel plate up to 1" (25 mm) thick.
OK Flux 350 is an active bonded flux for making butt and fillet welds in carbon steel plate up to 1" (25 mm) thick. It produces a smooth weld surface with uniform edges. The slag is generally free peeling. Its performance is very good even when the plate surface is covered with rust and mill scale. OK Flux 350 is suitable for use with AC or DC power in single or multiwire applications. It is recommended for butt welding of thin wall pressure vessels, rail cars, and structural steel plate. It is used for fillet welding in shipbuilding, pressure vessel, and structural applications. OK Flux 350 also is widely used as a backing flux in one sided welding. It provides good performance at currents up to 1100 amps.

| Typical Mechanical Properties | |
|---|---|
| As Welded | |
| Spoolarc 81 | |
| Tensile Strength | 80 ksi, 550 MPa |
| Yield Strength | 66 ksi, 455 MPa |
| Elongation in 2" | 26 % |
| CVN | 31 ft.-lbs., 42 J |
| Temperature | -20 °F, -29 °C |
| Spoolarc 80 | |
| Tensile Strength | 76 ksi, 525 MPa |
| Yield Strength | 62 ksi, 425 MPa |
| Elongation in 2" | 30 % |
| CVN | 36 ft.-lbs., 49 J |
| Temperature | -20 °F, -29 °C |
| Spoolarc 29S | |
| Tensile Strength | 87 ksi, 600 MPa |
| Yield Strength | 71 ksi, 490 MPa |
| Elongation in 2" | 28 % |
| CVN | 24 ft.-lbs., 32 J |
| Temperature | -20 °F, -29 °C |
| Typical Undiluted Weld Metal Analysis | |
| As Welded | |
| Spoolarc 81 | |
| C | 0.04 % |
| Mn | 1.80 % |
| Si | 0.70 % |
| P | 0.022 % |
| S | 0.010 % |
| Spoolarc 80 | |
| C | 0.05 % |
| Mn | 1.40 % |
| Si | 0.50 % |
| P | 0.022 % |
| S | 0.015 % |
| Spoolarc 29S | |
| C | 0.04 % |
| Mn | 1.90 % |
| Si | 0.90 % |
| P | 0.023 % |
| S | 0.015 % |
| Basicity Index: | 0.9 |
| Chemical Composition: | |
| SiO2 + TiO2 | 40 |
| Al2 + MnO | 20 |
| CaO + MgO | 25 |
| Fluorides | 5 |
| Flux Consumption | |
| (lb. Flux / lb. Wire) | |
| Voltage | DC+ |
| 26 | 0.61 |
| 30 | 0.83 |
| 34 | 1.4 |
| 38 | 1.36 |
All listed prices are in U.S. dollars and represent the Manufacturer's Suggested Retail Price (MSRP) for sale in the United States. Actual selling price will be determined by the Distributor. Prices are subject to change without notice.