Strength evaluation of brazing filler metals and brazing joints is not as straight forward as measuring the strength of bulk material. Höganäs follows the standards, SS-EN 12797 and EN-10002-1, to evaluate the strength of all BrazeLet® brazing filler metals. The method of choice is the butt joint made of the common stainless steel alloy 316L. The evaluation process is extensive and requires two separate machining steps with a brazing process in between. The final geometry is then tested in a traditional tensile testing machine.
The average strength is a quick way to get a feel for the difference between brazing filler metals but the complexity is much greater in reality. Nickel and Iron based filler metals form vastly different microstructures depending gap size (among other things) and these differences in microstructure have a large impact on the strength of the brazed joint. There are also physical effects on strength as gap size shrinks which has to do with necking of the material being drastically reduced in thin gaps.