Agglomerated Welding Flux BF 6.5

Flux type: Fluoride-Basic

ISO 14174: S A FB 1 67 AC H5 *)
(EN 760: SA FB 1 67 AC H5)


A semi-basic multi-purpose flux suitable for single and multi-wire (up to 5 wires) SAW-processes. The flux exhibits good weldability characteristics over a wide range of welding parameters and is characterized by a low consumption rate. BF 6.5 is especially recommended for longitudinal pipe fabrication (two-run or multi-layer technique) due to its high welding speed characteristic. Weld bead performance and slag release, even in narrow gaps, are excellent providing flat welds with low reinforcement and flat weld interfaces free from undercuts. The flux shows a high resistance to abrasion and a low consumption rate with good flux feeding properties in the transport and recovery system. As a result of low hydrogen levels (max.5ml/100g), oxygen levels of about 350 ppm and low nitrogen levels (max. 70 ppm) in the weld deposits, uniform mechanical properties with low temperature toughness are obtained. 


Manufacture of helical (spiral) and longitudinal seam steel pipes in grades L360 or X52 to L555 or X80 according to ISO 3183 / API Spec. 5L with appropriate filler metals.
Non-alloy and low-alloy structural steels acc. to EN 10025; boiler steels such as 16Mo3 / A335 Gr. P1 and 13CrMo4- 5 / A387Gr. 12; fine-grain structural steels with yield strengths up to 700 MPa observing the specific material requirements.

Characteristic chemical constituents

SiO2 + TiO2Al2O3 + MnOCaO + MgOCaF2
20 % 30 % 30 % 17 %
Basicity according to Boniszewski: ~1.7

Metallurgical behaviour acc. to ISO 14174 type of current DC

Pick-up Silicon
Pick-up Silicon
Pick-up/Burn-out Manganese
Pick-up/Burn-out Manganese

Flux density: 0.95 kg / dm3 (l)
Grain size acc. to ISO 14174: 2 – 20 (Tyler 8 x 65)
Current-carrying capacity: up to 1.000 A (DC or AC) using one wire

*) Diffusible hydrogen content H5: determined in deposited metal acc. to the method described in ISO 3690
Type of current DC; redrying conditions 200 ± 50°C


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