What is Stud Welding -Process , Types Of Stud Welding

Introduction to Stud Welding :

Stud welding is an economical, rapid fixing method of metals used both in engineering and construction work in heavy sections. Stud means a protecting know-pin or a large-headed nail which can apply the fixing or fastening method of a variety of shapes and diameters to the parent plate.

Therefore, a rapid reliable joining fastener is made. The studs may be of circular or rectangular cross-section, plain or threaded—internally or externally—and vary from heavy support pins to clips or attachments used in component assembly.

There are three common techniques of Arc stud welding:

Drawn arc stud welding
Short arc stud welding
Gas arc stud welding

Drawn arc Stud Welding :

The Drawn arc method is generally used for heavier studs and plates. The Capacitor discharge method is for light gauge sheets. The operation depends upon the size, shape, and material of the stud and the composition and thickness of the metal parts.

Drawn arc process is used in both engineering and heavy construction work. The equipment consists of a D.C. power source controller and a hand-operated gun or holder. The hand-operated gun has a operating solenoid and return-spring within the gun-body which carries the operating adjustment switch. Studs are fluxed on the contact end, which is slightly pointed, and are supplied with ferrules

To operate the equipment, the welding current and time for the diameter of the stud are selected, the stud is loaded into the proper chuck, the legs adjusted for length and the stud positioned on the plate. When the gun switch is pressed a low current flows between the pointed stud end and the work-piece and immediately the stud is raised, drawing an arc and ionising the gap.

Studs from 3.3-20 mm and above in diameter can be used on the plate thicker than 1.6 mm and above. The rate of welding varies with the type of work, jigging, location, etc. In circular and rectangular cross-section for engineering and construction industries the weld can be made in mild steel, austenitic stainless steel, aluminium, and its alloys, etc.

The Benefits of Stud Welding
Stud welding has many advantages over other joining processes:

It is fast. Welding a 3/4” fastener will take less than one second.
It is single sided. This means that access to the other side of the work piece is not required.
It is secure. Unlike the peripheral weld that would be used to weld a bolt in place,a stud weld is a full cross sectional weld. This means the full face of the fastener is welded in place providing a strong, worry-free weld.
It is cosmetically superior. As a single sided fastener there are no indicators that a fastener is attached.
It is welded and will not work free like a press-in fastener
Requires no special skills and little training to install.