Burst of screw head at the compression - 1.7034
It can come to bursts at the wire surface of cold upsetting steels by the compressing to screws or tools. The strength of the bursts is dependent from the degree of the cold forming, the size of the existing defects and possible anomalies of the structure. Pre-material defects were the reason for the processing problems, in this case with an slag in surface proximity.
Rod wire 18,00 mm round - spheroidised , pickled
following compressed to screws , quenched and tempered