AWS electrode specification for SMAW
Welding electrodes (welding rod) also called Shielded Metal Arc Welding (SMAW) welding rod which an electrode is a metal wire that is coated. It is made out of materials with a similar composition to the metal being welded. There are a variety of factors that go into choosing the right electrode for each project. SMAW or stick electrodes are consumable, meaning they become part of the weld, while TIG electrodes are non-consumable as they do not melt and become part of the weld, requiring the use of a welding rod. The MIG welding electrode is a continuously fed wire referred to as wire.
Electrode selection is critical to ease of cleanup, weld strength, bead quality and for minimizing any spatter. Electrodes need to be stored in a moisture free environment and carefully removed from any package.
Electrode is an object that is used to perform electric welding which functions as a burner which will cause an arc of fire. Electrodes, especially those used in SMAW welding or stick welding have a code or symbol where the code implies tensile strength, welding position and certain types of chemicals as flux. Likewise with how to use each type of welding wire.
According to the regulations of the American Welding Society (AWS), the electrode specifications for mild steel are regulated in AWS A5.1 which is marked with the letter ‘E’ and followed by a 4 number behind. The number behind which shows the alloying elements.
For more details, here’s ‘How to Read the Code’ for SMAW welding electrode on several types of carbon steel & stainless steel.
1. Electrodes For Mild Steel
AWS A5.1 Specification for Carbon Steel Electrodes for Shielded Metal Arc Welding
This type of SMAW welding wire is indicated by the Exxxx code (4 number).
For example, E6012 welding wire, how to read it is:
E = electrode for SMAW welding type
E60xx = the first two digits (number 60) indicate the tensile strength in Ksi (kilopound-square – inch).
The number 60 means the tensile strength is 60 ksi, if the number 70 means 70 ksi. When read in terms of ‘psi (pound square inch)’ is equal to 70000 psi, where 1 Ksi = 1000psi.
Exx1x = third digit (number 1) is the welding position.
numeric code 1 – for all positions
numeric code 2 – for flat and horizontal positions
code number 3 – only for flat positions.
Exxx2 = fourth digit (number 2) indicates:
– kind of salute
– arc penetration
– welding current
– iron powder (%)
Another example is the type of welding electrode E7018, which means:
– SMAW Electrodes
– 70000psi tensile strength
– can be used all positions (flat, horizontal, vertical and overhead)
– medium penetration, AC / DC power, film content of iron powder 25% -40%, low hydrogen.
With a strong enough tensile strength, the electrode of the E70xx type is widely applied for welding pressure pipes, furnaces, construction and others. While the E60xx type because of its only 60,000 psi tensile strength, it is usually only for tack weld and non-pressure welding, for example fencing and others.
2. Low Alloy Steel Electrodes
AWS A5.5 : This specification prescribes requirements for the classification of low-alloy steel electrodes for shielded metal arc welding of carbon and low-alloy steels. These electrodes include steel alloys in which no single alloying element exceeds 10.5%.
This specification prescribes the requirements for classification of low-alloy steel covered electrodes used for shielded metal arc welding. The requirements include chemical composition and mechanical properties of weld metal, weld metal soundness, usability tests of electrodes, and moisture tests of the low-hydrogen electrode covering. Requirements for standard sizes and lengths, marking, manufacturing, and packaging are also included.
The wrapped weld wire specification for Low Alloy Steel is set to AWS A5.5.
With the same code as the mild steel electrode followed by a line (dash) and letters and numbers as an alloying element, namely:
A = added element carbon molybdenum
B = added the element chromium molybdenum
C = added nickel steel
D = added element of manganese molybdenum molybdenum
G = added other elements
The final R code = indicates resistance to moisture pickup (80% humidity, 80ºF, 9 hours).
Examples of electrodes include: E7018-H8R, E8018 – B2H4R and others.
How to read :
Welding wire E7018-H8R means 70ksi strength, contains “iron powder-iron oxide-iron powder-iron oxide”, contains little hydrogen (low hydrogen), is resistant to water vapor and is for use in welding mild steel.
Welding wire: E8018-B2H4R means 80ksi strength, contains iron powder iron oxide, combined with chrome moly and low hydrogen, resistance to water vapor and is used to weld chrome moly steel alloys.
3. Stainless Steel Electrodes
AWS A5.4 specify the requirements for the classification of covered stainless steel electrodes for shielded metal arc welding.
The first three (3) digits are the AISI type number of stainless steel. Then followed by a line and 2 numbers. Example: E316-16, E308-16, E309-16 and others.
Two numbers after the meaning:
– Number 15 = the layer contains CaO, TiO2 & the current is DCRP.
– Number 16 = the layer contains TiO & K2O & the current is DCRP or AC.
– Number 17 = the layer contains CaO, TiO2 K2O SiO O SiO2 & the current is DCRP or AC.
Stainless welding rod AWS A5.4 E308-16
AWS A5.4 E308-16 is a kind of Titanium calcium type coating Cr19Ni10 stainless steel electrode. The deposited metal has good mechanical properties and intergranular corrosion resistance. It has good welding performance and porosity resistance. Heat resistance coating and crack resistance. AC/DC both can be applied.
AWS A5.4 E308-16 is suitable for used for welding the corrosion resistant stainless steel structure, such as 06Cr19Ni10 and 06Cr18Ni11Ti and their working temperature should be below 300℃
Stainless Welding rods AWS A5.4 E308L-16:
AWS A5.4 E308L-16 is a kind of Titanium calcium type coating with ultra-low carbon Cr19Ni10 stainless steel electrode. Carbon content of deposited metal is less than or equal to 0.04%. The intergranular corrosion resistance is good. Excellent welding performance and heat resistance, high strength coating, the porosity resistance is good. AC/DC both can be applied.
AWS A5.4 E308L-16 is suitable for used for welding ultra-low-carbon Cr19Ni10 stainless steel structures, and also used for 06Cr18Ni11Ti corrosion-resistant stainless steel structures whose working temperature is lower than 300°C. Mainly used in the manufacture of synthetic fiber, chemical fertilizer, oil and other equipment
Based on all the explanations above regarding how to read the meaning of the code on welding wire, we can draw conclusions and apply it to welding in the field / site. And it is answered already, why does construction welding, pipe and other steel industries use electrodes of the E70xx type and not E60xx.