Expert Welder "Explains" Electrodes

Expert Welder "Explains" Electrodes WELDERS/TORCHES Welders/Torches 26-2-40 Expert welder Stan McDonald, inventor of a variety of welding and shop tools, recently wrote the following explanation of different arc welding rods. "People are always asking me what the difference is between rods so I finally decided to write it down," says McDonald. Electrode Identification Electrodes are identified using the A.W.S. (American Welding Society) numbering system and are generally made in sizes from 1/16 to 5/16 in. For example, a common electrode is a 1/8-in. E6011. The numbers and letters tell you what it is: The rod is 1/8-in. dia. 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 of the weld that the rod will produce. So, "E60xx" indicates 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. • Exx1x is for use in all positions • Exx2x is for use in flat and horizontal positions • Exx3x is for flat welding The last two digits together indicate the type of coating on the elecrode and the welding current the electrode can be used with. Such as DC straight (DC-), DC reverse (DC+), or AC. SMAW welding (shielded metal arc welding) is performed using either AC or DC current. 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. With DC straight (DC- or DCSP) the weld will have a faster melt off and deposit rate, and thus will have medium penetration. AC current changes its polarity 120 times a second by itself so the polarity cannot be changed like DC current. Here are examples of the type of current each will work with: Electrodes & Currents Used Exx10 - DC+ (DC reverse or DCRP) Exx11 - AC or DC- (DC straight or DCSP) Exx12 - AC or DC- Exx13 - AC, DC-, or DC+ Exx14 û AC, DC-, or DC+ Exx15 û DC+ Exx16 û AC or DC+ Exx18 û AC, DC-, or DC+ Exx20 û AC, DC-, or DC+ Exx24 û AC, DC-, or DC+ Exx27 û AC, DC-, or DC+ Exx28 û AC or DC+ Here are four widely used electrodes for welding of mild steel. E6010 û 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 û This electrode has the same characteristics of the E6010, but can be used with AC and DC currents. E6013 û This electrode can be used with AC and DC currents. It produces a medium penetrating weld with a superior weld bead appearance. E7018 û 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 penetrration. Contact: FARM SHOW Followup, Stan McDonald, 402 Rosedale Ave., Foxboro, Ont. K0K 2B0 Canada (ph 613 968-9516; E-mail: smcdonal@kos.nert).

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