INTRODUCTION
There are many different types of electrodes used in the shielded metal
arc welding, (SMAW) process. The intent of this guide is to help with the
identification and selection of these electrodes.
ELECTRODE
IDENTIFICATION
Arc welding electrodes are identified using the A.W.S, (American Welding
Society) numbering system and are made in sizes from 1/16 to 5/16 . An example
would be a welding rod identified as an 1/8" E6011 electrode.The electrode
is 1/8" in diameter
The "E" stands for arc welding electrode.
Next will be either a 4 or 5 digit number stamped on the electrode. The
first two numbers of a 4 digit number and the first 3 digits of a 5 digit
number indicate the minimum tensile strength (in thousands of pounds per square
inch) of the weld that the rod will produce, stress relieved. Examples would be
as follows:
E60xx would have a tensile strength of 60,000 psi E110XX would be
110,000 psi
The next to last digit indicates the position the electrode can be used
in.
1. EXX1X is for use in
all positions
2. EXX2X is for use in
flat and horizontal positions
3. EXX3X is for flat
welding (Eg. E7018)
The last two digits together, indicate the type of coating on the
electrode and the welding current the electrode can be used with. Such as DC
straight, (DC -) DC reverse (DC+) or A.C.
I won't describe the type of coatings of the various electrodes, but will
give examples of the type current each will work with.
ELECTRODES AND
CURRENTS USED
- EXX10 DC+ (DC reverse or
DCRP) electrode positive.
- EXX11 AC or DC- (DC straight
or DCSP) electrode negative.
- EXX12 AC or DC-
- EXX13 AC, DC- or DC+
- EXX14 AC, DC- or DC+
- EXX15 DC+
- EXX16 AC or DC+
- EXX18 AC, DC- or DC+ (Eg. E7018)
- EXX20 AC ,DC- or DC+
- EXX24 AC, DC- or DC+
- EXX27 AC, DC- or DC+
- EXX28 AC or DC+
CURRENT TYPES
SMAW is performed using either AC or DCcurrent. Since DC current flows
in one direction, DC current can be DC straight, (electrode negative) or DC
reversed (electrode positive). With DC reversed,(DC+ OR DCRP) the weld
penetration will be deep. DC straight (DC- OR DCSP) the weld will have a faster
melt off and deposit rate. The weld will have medium penetration.
Ac current changes it's polarity 120 times a second by it's self and can
not be changed as can DC current.
ELECTRODE SIZE AND
AMPS USED
The following will serve as a basic guide of the amp range that can be
used for different size electrodes. Note that these ratings can be different
between various electrode manufactures for the same size rod. Also the type
coating on the electrode could effect the amperage range. When possible, check
the manufactures info of the electrode you will be using for their recommended
amperage settings.
Electrode Table
|
|
ELECTRODE DIAMETER (THICKNESS)
|
AMP RANGE
|
PLATE
|
|
1/16"
|
20 - 40
|
UP TO 3/16"
|
|
3/32"
|
40 - 125
|
UP TO 1/4"
|
|
1/8
|
75 - 185
|
OVER 1/8"
|
|
5/32"
|
105 - 250
|
OVER 1/4"
|
|
3/16"
|
140 - 305
|
OVER 3/8"
|
|
1/4"
|
210 - 430
|
OVER 3/8"
|
|
5/16"
|
275 - 450
|
OVER 1/2"
|
|
Note! The thicker the material to be welded, the higher the current
needed and the larger the electrode needed.
SOME ELECTRODE TYPES
This section will briefly describe four electrodes that are commonly
used for maintenance and repair welding of mild steel. There are many other
electrodes available for the welding of other kinds of metals. Check with your
local welding supply dealer for the electrode that should be used for the metal
you want to weld. E6010 This electrode is used for all position
welding using DCRP. It produces a deep penetrating weld and works well on
dirty,rusted, or painted metals
E6011 This electrode has the same characteristics of the E6010, but can
be used with AC and DC currents.
E6013 This electrode can be used with AC and DC currents. It produces a
medium penetrating weld with a superior weld bead appearance.
E7018 This electrode is known as a low hydrogen electrode and can be
used with AC or DC. The coating on the electrode has a low moisture content
that reduces the introduction of hydrogen into the weld. The electrode can
produce welds of x-ray quality with medium penetration. (Note, this electrode
must be kept dry. If it gets wet, it must be dried in a rod oven before use.)
It is hoped that this basic
information will help the new or home shop welder identify the various types of
electrodes and select the correct one for their welding projects.
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6010: Deep penetration with a
smooth arc and low spatter. Ideal for use on farm and road equipment, tanks,
piping, wrought iron, building structures, jigs, fixtures and general
maintenance. DC electrode positive unit must be run on DC welder.
6011: Popular electrode for
utility type welders. Works well on rusty, dirty steel. Deep penetration allows
for use on bridges, pressure vessels, farm and road equipment, building
structures, tanks and pipe. Similar to 6010, but can be used on AC or DC
current. Ideal for use on AC welders.
6013LV : Easy operation with a soft
arc make it ideal for sheet metal use. Especially poor fitting applications and
general repair on light thickness fabrication. AC/DC electrode works well on
low cost hobby type welders.
7014: Iron powder coating allows
for higher welding speeds and use of a drag technique. Easier to use than most
electrodes. AC/DC electrode works well on poor fitting joints and welds
requiring a very flat bead.
7018: High quality weld for mild
steel makes this the first choice for field construction applications where
weld quality is critical. Ideal for carbon steel where cracking is a concern.
Keep in a sealed container or an electrode oven when not in use. DC electrode
positive.
7018 AC: Designed to operate on AC
welders. Easier to operate than most other low hydrogen electrodes. Preferred
for its high purity, crack resistant welds on mild and carbon steels.
80LV Red: AC/DC straight or reverse
polarity, all position electrode can be used with low voltage machines for
short, intermittent or tack welds on thin, medium and heavy sections of mild
steel.
252: Welds 310 and 314
stainless subjected to corrosion at elevated temperatures as well as dissimilar
steels and stainless of unknown analysis.
275: Produces high tensile and
yield strengths on tool, high alloy, string, stainless, aircraft, nickel clad
and dissimilar steels.
HY-10: Special high strength
electrode is machinable and ideal for joining or build up of low alloy and
sulphur steels.
8: Provides a high nickel
machinable deposit for welding parts, filling holes and defects and salvaging
imperfect castings on thin sections of cast iron. Meets AWS A5.15 Class ENiCl-A.
8-60: Nickel electrode provides
machinable deposits with high strength and good ductility for heavy sections of
cast iron and ductile iron. Meets AWS A5.15, Class ENiFeCl-A.
6: Provides high strength,
dense, sound welds on cast iron where machinability is not needed. Excellent
for dirty or grease soaked castings.
4-60: Straight or
reverse polarity electrodes provide strong machinable, crack resistant and
spatter free deposits without porosity. Fort heavy sections of cast iron,
ductile iron, and dissimilar metals. Will not overheat at rated amperage.
24 AC/DC: AC/DC all position
electrode produces sound, porosity-free deposits on bronze, brass, copper, cast
iron and steel. Joins dissimilar metals or overlay on cast iron or steel.
34 DC: Premium DC reverse, all
position, aluminum electrode for joining, build up, cladding and reinforcing of
aluminum sheets, plates and castings of 1/8″ or thicker. Has extruded coating,
and leaves dense smooth deposits that provide good color match to base metal.
308L AC/DC: Excellent wetting action
and bead appearance makes this all position electrode ideal for welding most
types of 18-8 stainless steel (304,302). Deposit is highly resistive to
corrosion.
309L AC/DC: Higher corrosion
resistance and strength than type 308 make this all position electrode ideal
for 304 to 309 and 308 to carbon steels. Excellent weld appearance.
316L AC/DC: Provides a
stable smooth arc and fine spray metal transfer with a uniform bead that is
flat or slightly concave with straight edges. Penetration is complete and the
weld metal is free from porosity. Also has good out-of-position
characteristics. For 316L and 318 type steels in the chemical industry. Maximum
of .03% carbon deposit.
308L-17: Used in paper and chemical
industries, food processing equipment, dairies, breweries, distilleries,
kitchens and hospitals for welding Cr/Ni steels such as 304L, 308L, 301, 303,
304 and 309.
309L-17: AC/DC reverse, all
position electrode for welding carbon steels to stainless at service
temperatures below 600 degrees Fahrenheit.
316L-17: AC/DC reverse, all
position electrode, low-carbon electrode for join 316 and 316L stainless
subject to corrosive media.
HS-2C: Hard facing electrode for
severe abrasion and moderate impact with hardness 58-62 Rockwell C.
HS-65W: Hard facing
electrode for superior wear resistance involving extreme abrasion with hardness
63-67 Rockwell C.
Ni-Matrix: All position hard facing
electrode for constant heavy impact and abrasion with hardness 48 Rockwell C.
Super Join-M: Hard facing
electrode resistant to corrosion from water and mild corrosives with severe
impact protection on manganese steel and unknown iron base metals.
Chamfer Rod: AC/DC straight all
position gouging electrode for ferrous and non-ferrous metals.
Stud Plus: AC/DC reverse polarity gouging electrode for
removing broken studs and bolts.
