BS 1140 Spot Welding Test -Whats Involved?
The BS 1140:1993 Specification for resistance spot welding of uncoated and coated low carbon steel specifies a testing procedure for coated materials and is particularly applicable to the vehicle body repair industry.
The technician has to produce two spot welds on 1.2mm steel welding tags of varying diameters-usually 5mm and 8mm.
The welds are to be performed in manual mode showing that the technician can set up the machine correctly and adjust accordingly to obtain the desire nugget size.
They need to then adjust the welder to obtain the higher sized nugget.
Welds should be produced without splash or explusion from the weld joint and if this is observed the technician should be able to adjust the machine to control this.
Visual inspection is carried out and the nugget diameter and HAZ size is observed to see if it meets approval.
A general rule is that the width of the HAZ or burn ring should not exceed half of the width of the nugget diameter.
The technician is required to show how to carry out a peel test and observe the results.