Arc Welding Robots 101

Mar 17, 2016

Robotic arc welding is becoming increasingly more popular as technology continues to advance and automation systems become more affordable. Automated arc welding is able to accurately and consistently produce quality welds, providing for a happy and satisfied manufacturer and customer.

Multiple arc welding robots

What is arc welding?

Arc weld­ing fus­es parts per­ma­nent­ly togeth­er by using a pow­er sup­ply to gen­er­ate an elec­tric arc between an elec­trode mount­ed in a torch and a met­al. This arc is an elec­tric cur­rent flow­ing between two elec­trodes through an ion­ized col­umn of gas is able to pro­duce a heat intense enough to melt the metal. 

The heat is pro­duced through a neg­a­tive­ly charged cath­ode and a pos­i­tive­ly charged anode. The neg­a­tive and pos­i­tive ions are bounced off of each oth­er in the plas­ma col­umn at an accel­er­at­ed rate. The elec­trode is typ­i­cal­ly a spe­cial­ly pre­pared rod or wire that not only con­ducts the cur­rent but also melts and sup­plies filler met­al to the joint.

The arc is formed between the actu­al work and an elec­trode (stick or wire) that is guid­ed along the joint. It pro­vides the heat need­ed to melt the elec­trode and the base met­al, and some­times also sup­plies the means to trans­port the molten met­al from the tip of the elec­trode to the work. 

This intense heat (around 6500ºF at the tip) applied at the joint between two parts is melt­ed and caused to inter­mix with an inter­me­di­ate molten filler met­al. This heat melts both the base met­al and the elec­trode, cre­at­ing molten droplets that are detached and trans­port­ed to the work through the arc col­umn when the elec­trode is consumable. 

In car­bon or TIG weld­ing there are no molten droplets to be forced across the gap and onto the work so filler met­al is melt­ed into the join from a sep­a­rate rod or wire.

Regard­less, this pool of molten met­al is some­times called a crater.” The crater solid­i­fies behind the elec­trode (see slag” below) as it is moved along the joint. The result is a met­al­lur­gi­cal fusion bond that pro­duces a weld­ment that has a sim­i­lar strength to the met­al of the parts. This is dif­fer­ent than non-fusion process­es of join­ing where the mechan­i­cal and phys­i­cal prop­er­ties of the base mate­ri­als can­not be dupli­cat­ed at the joint.

This met­al trans­fer can occur one of two ways: Sur­face Ten­sion Trans­fer where a drop of molten met­al touch­es the molten met­al pool and is drawn into it by sur­face ten­sion or Spray Arc where the drop is eject­ed from the molten met­al at the elec­trode tip by an elec­tric pinch pro­pelling it to the molten pool (great for over­head welding).

Pow­er­ing Arc Welding

There must be an ion­ized path to con­duct elec­tric­i­ty across a gap and then some sort of igni­tion in order to start the arc. This is usu­al­ly caused by a pow­er source sup­ply­ing an ini­tial volt­age high enough to cause a dis­charge or by touch­ing the elec­trode to the work and then with­draw­ing it as the con­tact area becomes heated.

When weld­ing, one can use a direct cur­rent (DC) with the elec­trode either pos­i­tive or neg­a­tive or alter­nat­ing cur­rent (AC). The choice of cur­rent and polar­i­ty depends on the process, the type of elec­trode, the arc atmos­phere, and the met­al being weld­ed. What­ev­er pow­er source is nec­es­sary is fit­ted with nec­es­sary con­trols that are con­nect­ed by a work cable to the work piece. 

Arc Shield­ing

Arc shield­ing is a nec­es­sary process in arc weld­ing as any met­al at high tem­per­a­tures has a high­er reac­tiv­i­ty to chem­i­cal ele­ments in the air. So, the process has a means of cov­er­ing the arc and molten pool with a pro­tec­tive shield of gas. Shield­ing gas is used while the torch is join­ing parts togeth­er in order to pre­vent con­t­a­m­i­na­tion. This also con­firms the strength of welds and min­i­mizes post-weld cleanup of a part.

Robot­ic Arc Welding

Since the 1980s, weld­ing automa­tion has become a much more robust and mature process. It has advanced quick­ly and has become extreme­ly effec­tive at meet­ing tedious pro­duc­tion demands at fast rates, while also being eco­nom­i­cal, effi­cient, depend­able, and enabling fur­ther pro­tec­tion of work­ers from dan­ger­ous tasks. 

6‑axis robot sys­tems are able to more than mim­ic a human arm’s move­ment with­in a cell and allow the torch to be placed exact­ly where nec­es­sary in order to work in the most effi­cient, repeat­able posi­tion. For exam­ple, Fanuc weld­ing robots can improve qual­i­ty, increase pro­duc­tiv­i­ty, and low­er costs.

In just about every indus­try, big or lit­tle, weld­ing is used as a prin­ci­pal means of the fab­ri­ca­tion and repair process­es for prac­ti­cal­ly any appli­ca­tion. Robot­ic weld­ing includes process­es like arc weld­ing, MIG weld­ing, TIG weld­ing, laser weld­ing and spot weld­ing.

These ben­e­fits are caus­ing the weld­ing robot mar­ket to yield growth rates faster than any oth­er indus­tri­al robot. This is evi­dent in the esti­mate that the auto­mat­ed weld­ing and acces­sories divi­sion alone will be worth $9.8 bil­lion in 2028.

Ben­e­fits of Robot­ic Welding


Robot­ic weld­ing sys­tems are mas­ters at get­ting the job done quick­ly. Robots don’t have any required lunch breaks nor need­ed vaca­tion times; they will work con­tin­u­ous­ly with­out inter­rup­tion, 247. There is less han­dling com­pared to a man­u­al weld cycle so the robot achieves much high­er lev­els of arc-on time and typ­i­cal­ly will increase out­put by a fac­tor of two to four. Sub­se­quent­ly, you will see a dra­mat­ic increase in your through­put and pro­duc­tiv­i­ty that increas­es your company’s over­all efficiency.


Robot­ic sys­tems have reg­u­la­tions that enable them to make few­er errors than a man­u­al weld­ing sys­tem which helps to decrease wast­ed mate­r­i­al and time. There are also designs to help reach dif­fi­cult or slim places, such as a slen­der robot­ic arm.


The reg­u­la­tions and result­ing accu­ra­cy pro­duce weld­ments that are extreme­ly con­sis­tent. This increas­es the con­fi­dence in the prod­uct qual­i­ty, every sin­gle time.


Weld­ing can be a very dan­ger­ous appli­ca­tion as it deals with flash, fumes, sparks and heat. When you auto­mate, you are able to pro­tect work­ers as the robots can endure these haz­ards. Employ­ees claim­ing com­pen­sa­tion if they are put in harm’s way can also be reduced. Com­pa­nies can reduce the risk of their employ­ees claim­ing com­pen­sa­tion if they are affect­ed by the haz­ardous work­ing environment.

Cost Reduc­tion

The cost of man­u­al weld­ing can be steep as it requires time, skill, and con­cen­tra­tion. Robot­ic weld­ing takes less time and allows you to cut costs of direct labor, con­serve ener­gy (few­er start-ups), and con­serv­ing mate­ri­als. Insur­ance and acci­dent relat­ed costs are also reduced. The cost sav­ings that robot weld­ing brings can help com­pa­nies to be more com­pet­i­tive with low cost man­u­fac­tur­ing coun­tries in East­ern Europe or China. 


A robot has an excel­lent path fol­low­ing accu­ra­cy and can present a weld­ing gun at the cor­rect weld­ing angle, speed, and dis­tance at a very high repeat­able accu­ra­cy (± 0.04 mm). This presents the abil­i­ty for opti­mum weld­ing con­di­tions to be used for each and every joint which results in con­sis­tent high qual­i­ty out­put, 247, with reduced costs for rework, scrap, wire con­sump­tion, or removal of weld splatter.


Man­u­al weld­ing will always be required to some degree, but it brings its own sets of chal­lenges… train­ing, recruit­ment, and deal­ing with a high turnover rate all can come at high costs. Robot­ic automa­tion brings much more sta­bil­i­ty and depend­abil­i­ty for your company’s weld­ing job.


The robot can be used to weld many dif­fer­ent prod­ucts such as MIG, TIG, SMAW, FCAW, SAW, and PAW. This also allows com­pa­nies to pro­duce a vari­ety of prod­ucts with a very quick turnaround. 

Floor space

Com­pared to the same out­put from man­u­al weld­ing bays the robot requires less floor space.

    Get Start­ed with Robot­ic Arc Weld­ing Today

    The demand for arc weld­ing automa­tion sys­tems today is increas­ing­ly ris­ing as com­pa­nies are aware of the low avail­abil­i­ty in qual­i­fied welders par­al­leled by the increase in com­pe­ti­tion demands seen in the glob­al mar­ket. After view­ing all of the ben­e­fits and look­ing at your pro­ject­ed ROI, you should­n’t need any more convincing. 

    Don’t waste any more time, Robots​.com is ready to find you the per­fect arc weld­ing automa­tion sys­tem. We have over 35 years of expe­ri­ence, espe­cial­ly with arc weld­ing automa­tion. We have many dif­fer­ent new and used arc weld­ing robots and work­cells in stock ready for integration. 

    Con­tact Robots​.com online or call us at 8777626881 to get started.

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