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(SW)

Welding process in which a metal fastener (weld stud) is

joined to a workpiece

The metal fastener is joined under pressure once

sufficiently heated with an electric arc

The fastener or weld stud is positioned for welding

through the use of a stud gun

When the operator activates the stud gun trigger, thefastener (electrode) is welded to the workpiece without the

use of filler metal

The welding duration of SW is typically one second or less

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Principle of operation

This is a combination of arc welding and forge welding

It is based on two steps !irst, electrical contact between the end of the

stud and base metal occurs and an arc is established

The heat of the arc melts the surface of the end of the stud and thework surface

"s soon as the entire cross section of the stud and the area of e#ual

si$e on the base metal are melted ,the stud is forced against the base

metal

The molten end of the stud joins with the molten pool of the work

surface, and as the metal solidifies the weld is produced

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%ne end of a SW fastener is prepared for welding

" ceramic ferrule surrounding the weld end of the fastenerprovides partial shielding of the weld

The ferrule also dams the molten metal to form a fillet type

weld Shielding gases or flu& may or may not be used to protect

the weld

The polarity used in stud welding depends on the type ofmetal being used

Welding aluminum would usually re#uire '*

Welding steel would re#uire '+

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ST' W-'I+. (SW)

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Typical Uses

The arc stud welding process lends itself to a wide range of

applications such as"utomotive

Ship building

"ppliance

"ero/dynamics

0oilers

-ight or heavy construction

*reassembled fabrication designs

!it/up parts design

The process may be utili$ed on a range of material thickness

from about 121 in to several inches

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Applications

sed for welding studs to mild steels , low alloy steels, andsome of the austenitic stainless steels

apable of producing a full cross section weldment with a

minimum of base metal distortion or surface disruption

an be used in locations which do not permit use of other

fastening methods

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Applications Cont…

*rocess lends itself to the automatedconcept or high production shops

apable of producing welds which are lesscostly per unit than other methods

*rocess may be effectively utili$ed with aminimum of time spent in personnel training

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Equipment

onstant urrent () *ower Source

Stud Welding .un

Weld able With Stud .un

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2.3.

4.

5.6.

' () *ower

Source

.round

cable andlamp

Stud gun

(/)

*late (3)

W e l d

c a b l e

ontrol cable

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Poer Source

The typical power source for stud welding should

have the following characteristics4

○ '/ onstant urrent ()

○ %pen circuit voltage range of 51/611 7

○ 8apid current rise time

○ 9igh current output for relatively short timeperiods

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Wel!in" GunsThere are two basic arc stud welding guns available4

*ortable, pistol grip configuration, which is used for hand/

held or manual operation

!i&ed, production gun, which is usually mounted on apositioning device and is usually incorporated with an

automatic fastener loading system

The portable, pistol grip design is offered in three capacities4

-ight 'uty (Stud diameters :; mm to <= mm)

Standard 'uty (Stud diameters :; mm to 6=< mm)

9eavy 'uty (Stud diameters :; mm to :6> mm)

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T#e Wel!in" Stu!

Welding grade studs are made of most commercially

used metals, and normally range in diameters from

:; mm to :6> mm with lengths as re#uired

In addition to straight threaded or unthreaded studs,

it is possible to obtain a wide variety of shapes and

si$es

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Arc S#iel!s ($errules)

oncentrates the arc heat to the immediate weld area

*rotects the molten weld pool from atmospheric

contamination

onfines the molten metal to the weld $one, to form a fillet

*revents charring and disruption of surrounding base

metal surfaces

8educes the possibility of open arc flash? therefore, the

operator and surrounding personnel need only wear

suitable flash type safety glasses

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Wel! %uality

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Capacitor Discharge (CD) stud welding systems use a small

ignition tip at the ase o! the weld stud to produce an arc.

apacitor 'ischarge (') stud welding is generally

used to weld smaller diameter fasteners to thin base

metals

Since the entire weld cycle is completed in

milliseconds, welds can be made without pronounced

distortion and burn/through

%nly smaller studs of 2@ mm ma&imum diameter are

welded with this method

apacitor 'ischarge Stud Welding

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