In any industry, diagnostics, testing, and quality control are all critical parts of the fabrication process. In the stud welding industry, suppliers and manufacturers alike follow ISO 9001, ISO 13918, and many other regulations for testing in order to provide reliable, high-quality services, construction, and equipment. The stud welding process has several different operations, including drawn arc, capacitor discharge (CD), and short cycle welding. With each of these welding processes, welders should perform tests at the beginning of each job to ensure their tools are calibrated correctly, the right materials are used, and the surface is prepared sufficiently. Without these tests, operators could go on to finish a job with weak, brittle, or messy welds. Whether you’re working with handheld, portable units in the field or you operate a fully automated production line in a facility, you can find the supplies you need at Northland Fastening Systems (NFS). We offer a comprehensive range of studs, welding accessories, and tools for rent or purchase. We also provide a repair service for most models, and our own welding technicians are happy to give advice and guidance.
Stud Welding Process
While some tests in the stud welding process can vary from operation to operation, there are three standard tests that should be performed on at least 10 weld samples before a full project is begun. These tests include:
The bend test is a typical test that either confirms or denies the strength of the weld connection point. The stud is bent back and forth at opposing 30º-angles until the stud breaks or the connection point fails. If the stud fails first, the weld is correct. Another version of this test bends studs at a 90º-angle over a pin with four times the diameter of the stud. Studs that bend over the pin without the connection point failing are performed correctly. Fractures in the plate metal or the weld point are signs of a poorly performed weld.
Weld quality can also be measured for tensile strength. Tension or tensile tests are typically done on shear connectors and other stud systems that will face large amounts of tensile stress. In a tensile testing machine, force is applied to a stud until failure. If the stud fails at the tension point before the weld connection or welding surface shows damage, that weld is accurate.
With a torque test arrangement or torque testing device, welding points can also be measured for accuracy. While bend tests are destructive tests, causing the weld to fail, torque tests can be done without serious damage to the weld point. Torque tests use a torsion meter as defined stress is applied. If the deformation of the stud falls within acceptable ranges, the weld was performed correctly.