Agglomerated Welding Flux BF 3.5

Flux type: Aluminate-Basic

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


BF 3.5 is an agglomerated welding flux of the aluminate basic type. It is suitable for joint welding of low alloy structural steels, pipe steels, boiler steels and fine grain steels. The flux is suitable for single and multilayer welding of longitudinal and circumferential and fillet welds. It can be used for single, tandem, twin and multi wire welding systems. Excellent slag removal in narrow groove welds of thick wall sections. Typical characteristic of this flux is a medium Mn and Si pick up as well as very low diffusible hydrogen level. It is suitable for both AC and DC welding.


Joint welding of non-alloy and low alloy structural steels acc. to. EN 10025. Fine-grain structural steels with ys < 420 MPa and boiler steels such as P265GH (H II) and 16Mo3/A335 grade 91

Characteristic chemical constituents

SiO2 + TiO2Al2O3 + MnOCaO + MgOCaF2
20 % 30 % 30 % 15 %
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: 1.1 kg / dm3 (l)
Grain size acc. to ISO 14174: 2 - 16 (Tyler 10 x 65); 2 - 20 (Tyler 8 x 65)
Current-carrying capacity: up to 1,500 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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